Homework Help: Science: Physics

Recent Homework Questions About Physics

physics
You push a 1.3 kg block against a horizontal spring, compressing the spring by 22 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 79 cm from where you released it. The spring constant is 220 N/m. What is the coefficient of kinetic ...
Sunday, April 7, 2013 at 5:39pm

physics
3. In the figure, a runaway truck with failed brakes is moving downgrade at 107 km/h just before the driver steers the truck up a frictionless emergency escape ramp with an inclination of θ = 14°. The truck's mass is 1.4 × 104 kg. (a) What minimum length L ...
Sunday, April 7, 2013 at 4:12pm

physics
A 35,000 kg locomotive is moving at a velocity of 11 m/s east. What is the magnitude of the locomotive's momentum?
Sunday, April 7, 2013 at 3:24pm

physics
mc030-1.jpg Two stars are bound together by gravity. The larger star has four times the mass of the smaller star. Which diagram best illustrates the orbital motion of the two stars? (Note: the stars are shown much larger than they really are compared to the
Sunday, April 7, 2013 at 3:13pm

physics
Compared to the number of radians in one revolution of a bicycle tire with a radius of 33 centimeters, the number of radians in one revolution of a go-cart wheel (radius = 22 centimeters) is:
Sunday, April 7, 2013 at 3:11pm

physics
A rollercoaster car loaded with passengers has a mass of 2,000 kilograms. The track of the roller coaster has a semi-circular valley with a radius of 24 meters. If the vehicle has a speed of 18 m/sec at the very bottom of the valley, the force exerted on the vehicle by the ...
Sunday, April 7, 2013 at 3:09pm

Physics
Two parallel plates are separated by a dielectric of thickness 2 mm with a dielectric constant of 6. If the area of each plate is 40 cm^2 and the potential difference between them is 1.5 kV, determine (a) the capacitance
Sunday, April 7, 2013 at 3:07pm

physics
The Earth has a radius of about 6.38 ´ 103 kilometers at the equator and rotates 360° every 24 hours. The angular displacement of a person standing at the equator for 8.0 hours is:
Sunday, April 7, 2013 at 3:07pm

Physics
Platform area = 0.027[m2]. Wind Speed = 7.1[ms-1]. Air Density = 1[kg m-3]. Drag = 0.39[N]. Lift = 1.45[N]. Coeffecient of Lift = Use three sig. figs. or N/A if no answer. Platform area = 0.045[m2]. Wind Speed = 5.7[ms-1]. Air Density = 1[kg m-3]. Drag = 0.77[N]. Lift = 1.19[...
Sunday, April 7, 2013 at 2:45pm

Physics (fluids)
1. You have a large wind tunnel of cross-sectional area 0.61[m2]. The wind speed is 4[ms-1]. Assume air density is 1 [kgm-3]. The Drag is 2.3[N]. What is the coeffecient of drag for the shape that has diameter 7.32[cm]? . Use three sig. figs. or N/A if there is not enough ...
Sunday, April 7, 2013 at 2:36pm

Physics
1. You have a large wind tunnel of cross-sectional area 0.61[m2]. The wind speed is 4[ms-1]. Assume air density is 1 [kgm-3]. The Drag is 2.3[N]. What is the coeffecient of drag for the shape that has diameter 7.32[cm]? . Use three sig. figs. or N/A if there is not enough ...
Sunday, April 7, 2013 at 1:40pm

physics
A current I=2 Amperes flows in a circular single loop coil of radius R=10 cm. (a) Evaluate the magnitude of the magnetic field (in Tesla) at a point P on the axis of the coil, and a distance z =5 cm away from the plane of the coil itself. Now consider two N-turn circular coils...
Sunday, April 7, 2013 at 1:39pm

Physics
What is the coeffecient of drag for the shape that has diameter 7.32[cm]? . Use three sig. figs. or N/A if there is not enough information. 2. You have a large wind tunnel of cross-sectional area 0.95[m2]. You have a set of shapes that are all the same shape except they each ...
Sunday, April 7, 2013 at 1:37pm

Physics
Determine the electric potential energy for the array of three charges shown in the drawing, relative to its value when the charges are infinitely far away. (Let q1 = 8.48 µC, q2 = 19.2 µC, and q3 = -16.1 µC.)
Sunday, April 7, 2013 at 1:19pm

physics
A train accelarates uniformly in a straight line at 0.3m/s^2 from rest. Calculate the velocity 15 seconds after its departure. Calculate time taken to reach 30km/h and calculate Distance covered by the train
Sunday, April 7, 2013 at 10:16am

physics
A 63.8 N crate is pulled up a 5.22 m inclined plane by a worker at constant velocity. If the plane is inclined at an angle of 59 degree to the horizontal and there exists a constant frictional force of 32.6 N between the crate and the surface, what is the force applied by the ...
Sunday, April 7, 2013 at 9:44am

physics
A L=3 mile long conducting cable tethers a satellite to the International Space Station. The Cable moves through the Earth' magnetic field of about B=0.02 Gauss at a speed of v=8 km/sec. The cable points radially from the Space Station to the satellite. The ISS moves ...
Sunday, April 7, 2013 at 5:23am

Physics
A long coaxial cable consists of two concentric conductors. The inner conductor is a cylinder with radius R1, and it carries a current I0 uniformly distributed over its cross section. The outer conductor is a cylindrical shell with inner radius R2 and outer radius R3. It ...
Sunday, April 7, 2013 at 5:17am

Physics
A 500-turn circular coil with an area of 0.050 0 m2 is mounted on a rotating frame that turns at a rate of 20.0 rad/s in the presence of a 0.050 0-T uniform magnetic field that is perpendicular to the axis of rotation. What is the instantaneous emf in the coil at the moment ...
Saturday, April 6, 2013 at 11:25pm

Physics (Algebra-based)
A block starts at rest and slides down a frictionless track except for a small rough area on a horizontal section of the track.It leaves the track horizontally, flies through the air, and subsequently strikes the ground. gravity= 9.81 m/s^2. height1=4.1m---- is initially ...
Saturday, April 6, 2013 at 9:42pm

physics
A car travelling 19.4m/s passes apolice car at rest.As it passes, the police car starts up, accelerating with a magnitude of 3.2m/s. Maintaining that acceleration, how long will it take the police car to catch up with the speeding motorist?
Saturday, April 6, 2013 at 3:59pm

physics
A rectangular wire loop of dimensions a×b, with a=3.5 cm and b=4.5 cm, is pulled parallel to side a at a constant speed v=4.3 m/sec into a region where the magnetic field, |B|=0.125 T, is uniform and perpendicular to the loop. The loop enters the magnetic field at time t...
Saturday, April 6, 2013 at 3:21pm

physics
A 2 N neuton force is applied to a a2.5 Kg dry ice puck that moves frictionlessly across a desktop. If the puck starts at rest, how fast will it be moving after the force is applied? If the puck were moving at 0.6 m/x, how long would it take to bring the puck to a stop?
Saturday, April 6, 2013 at 3:15pm

physics
A boat is traveling on a bearing of 25 degrees East of North at a speed of 4 knots (a knot is 1.852 km/h). After traveling for 3 hours, the boats heading is changed to due South and it travels for an additional 2 hours at 5 knots. Using a Vector diagram, what is the resultant?
Saturday, April 6, 2013 at 2:33pm

Physics
For parts A-C: /^Vo | 2M | velocity into pg. ->R )2m ) ------ top view rear view A car of mass, 2m, is going around a turn at a constant radius, R, with velocity, v0. The turn is not banked – it is a flat surface. Assume the car and the road are on Earth’s surface...
Saturday, April 6, 2013 at 1:00pm

Physics
For this problem, you are allowed to consult with other members of the class, but not with faculty and not with anyone outside the course. Simplify all your expressions. A car of mass, 2m, is going around a turn at a constant radius, R, with velocity, v0. The turn is not ...
Saturday, April 6, 2013 at 12:48pm

Physics
in the moments before you hit a truck, you decide to calculate the impulsive force (impulse) you will feel. you and your bike have a combined mass of 120kg and the truck brings you to a halt in 0.3s. What is your impulse?
Saturday, April 6, 2013 at 9:09am

Physics
When catching a ball, your cricket coach advises you to move your hands backwards with the ball. Explain the physics behind this 'follow through' technique.
Saturday, April 6, 2013 at 6:08am

physics
Jenny is riding on a bus. She has been unable to find a seat and so she is standing in the aisle. Explain, in physics laws and principles, why it is important that she hold onto something while she is completing her journey.
Saturday, April 6, 2013 at 5:33am

Quantum Physics
Consider a particle whose wavefunction at some fixed time t is represented by -A if -2≤x≤0 ψ(x)= A if 0≤x≤3 0 otherwise (a) What is the normalization constant A? (b) What is the probability of finding the particle at a position x≤0? (c) What ...
Saturday, April 6, 2013 at 2:56am

physics
Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m2. Assuming that all the photons in the light have the same wavelength (in vacuum) of 478 nm, determine the number of photons per second per square meter that reach the earth.
Saturday, April 6, 2013 at 1:31am

Physics
A simple motor has N=250 turns of wire on a coil measuring 12 cm \times \, 4 cm. It's resistance is R=10 ohms. The magnetic field is B=1 T. (a) How much current (in Ampere) in the coil is needed to produce a maximum torque of 40 Nm? b) What maximum EMF (in Volts) is ...
Saturday, April 6, 2013 at 12:24am

Physics
The equation describing the (r, \theta ) coordinates of points along a single field line of a magnetic dipole is r=R_0 \sin ^2(\theta ) where \theta =0 is in the direction of the dipole moment and R_0 is a constant which is different for each field line. The question requires...
Saturday, April 6, 2013 at 12:14am

Physics
(a) In the diagram above the small semi-circle in the wire above R_1 indicates that it is not in contact with the horizontal wire which it appears to intersect due to the 2-dimensional projection. Additionally, the horizontal wire is continuous, not broken. Calculate |V_1| in ...
Friday, April 5, 2013 at 11:53pm

physics
On its highest power setting, a microwave oven increases the temperature of 0.350 kg of spaghetti by 45.0°C in 100 s. (a) What was the rate of power absorption by the spaghetti, given its specific heat is 0.900 kcal/kg·°C? W (b) Find the average intensity of the...
Friday, April 5, 2013 at 11:16pm

physics
A 2.10 m diameter university communications satellite dish receives TV signals that have a maximum electric field strength (for one channel) of 7.90 µV/m. (a) What is the intensity of this wave? W/m2? (b) What is the power received by the antenna? W? (c) If the orbiting ...
Friday, April 5, 2013 at 11:15pm

Physics
Light with a wavelength of 500 nm (5. 10-7 m) is incident upon a double slit with a separation of 0.28 mm (2.80 10-4 m). A screen is located 2.7 m from the double slit. At what distance from the center of the screen will the first bright fringe beyond the center fringe appear...
Friday, April 5, 2013 at 5:45pm

Physics
Light with a wavelength of 500 nm (5. 10-7 m) is incident upon a double slit with a separation of 0.44 mm (4.40 10-4 m). A screen is located 2.1 m from the double slit. At what distance from the center of the screen will the second dark fringe beyond the center fringe appear? ...
Friday, April 5, 2013 at 5:42pm

Physics
A figure skater rotates about a vertical axis through her center with both arms and one leg extended. Her rotation rate is 0.65 rev/s. She then pulls her arms and leg closer to her body and begins to spin at a 1.85 rev/s. What is the ratio of her new moment of inertia to her ...
Friday, April 5, 2013 at 5:27pm

PHYSICS
A truck has a momentum of 5.8x10^4 Ns [S]. An average force of 2.2x10^3 N [S] increases the truck's momentum for the next 8.8s. What is the impulse and final speed of the truck?
Friday, April 5, 2013 at 4:09pm

PHYSICS
Max is throwing a 57g tennis ball upward and hitting it (with a racket) when it reaches the top of its flight. If the racket exerts an average force of 440N on the ball, find the speed of the ball after the collision (if they are in contact for 4.5ms)
Friday, April 5, 2013 at 4:08pm

PHYSICS
A baseball of mass 148g is travelling at 35.0m/s [E] collides with a baseball bat. the collision lasts for 1.10ms. After the collision, the baseball travels at 52m/s [W]. What is the force of the bat on the baseball
Friday, April 5, 2013 at 4:07pm

Physics 1
A mass m1 = 4.9 kg rests on a frictionless table and connected by a massless string over a massless pulley to another mass m2 = 4.7 kg which hangs freely from the string. When released, the hanging mass falls a distance d = 0.8 m.
Friday, April 5, 2013 at 3:52pm

physics
If a body weight 10N is lifted from the floor to a table 2m above the floor ,calculate the potential energy gained.What happens to the energy if the body falls of the table and hits the floor?
Friday, April 5, 2013 at 2:00pm

physics
For a long straight wire, carrying a current of 20 A. A rectangular coil 5 x 10 cm2 is 2 cm apart. The coil carries a current of 5 A. a) determining the force acting on each segment of the rectangular coil. b) What is the net force on the coil?
Friday, April 5, 2013 at 1:50pm

physics
A police offer may warn that “speed kills.” In video games, high-speed crashes are common. Suppose a particular scene in a game required the following elements: • a high performance motorcycle must crash into a barrier and be stopped • a small scooter must ...
Friday, April 5, 2013 at 1:46pm

Physics
A force (in this case, water) is applied to a waterwheel that turns and lifts a small weight that is attached to a string that is attached to the waterwheel's axle. How do Newton's 3 laws of motion describe this event?
Friday, April 5, 2013 at 12:18pm

Physics
if a toy car's motor propelled it 1.905m in 7.1 seconds and it kept rolling .38m for 8.6 seconds what is the coefficient of friction between the wheels and the floor assuming that is the only source of friction. i know accel=.08m/s2 and -.12m/s2 but after that i got lost.
Friday, April 5, 2013 at 12:17pm

Physics
The diameter of the atom is proportional to n2, where n = 1 labels the lowest, or "ground" state, n = 2 is the second state, n = 3 is the third state, and so on. If the atom's diameter is 1 multiplied by 10-10 m in its lowest energy state, what is its diameter in...
Friday, April 5, 2013 at 12:02pm

physics
A flying bat emits squeaks at a frequency of 80 kHz. If a stationary observer picks up the frequency of the squeaks as 78 kHz, determine the speed at which the bat is flying
Friday, April 5, 2013 at 10:37am

physics
A 50kg gun mounted on wheels shoots a 3kg missile directed at an angle of 30 with a horizontal.if the muzzle velocity of missile is 550m/s what is the horizontal recoil velocity of the gun.
Friday, April 5, 2013 at 10:21am

Physics
A long coaxial cable consists of two concentric conductors. The inner conductor is a cylinder with radius R_1, and it carries a current I_0 uniformly distributed over its cross section. The outer conductor is a cylindrical shell with inner radius R_2 and outer radius R_3. It ...
Friday, April 5, 2013 at 5:42am

physics
a circular plastic dish of radious 2 cm is floating in a bucket of water. A small iron block is placed gently in it. It sink by 1cm find the mass of the block
Friday, April 5, 2013 at 3:57am

Physics
A 35kg child is swinging on a swing with length 2.8m to the bottom of the seat. At the highest point of the swing, the rope makes an angle of 42 degrees from vertical. Calculate the speed of the child at the bottom of the swing. Assume no thermal energy is created. Calculate ...
Friday, April 5, 2013 at 3:14am

physics
A person pushes with force F on a box which remains at rest on a rough floor as shown in the top figure. The bottom figures illustrates all the force acting on the box. a) What condition must be satisfied by all the force acting on the box so that it remains at rest? Draw a ...
Friday, April 5, 2013 at 1:13am

physics
A box is being lowered down a wall at constant speed by a girl, as shown. Her hand is pushing on the edge of the box with 50 N of force at a 45◦ angle with respect to the horizontal. The box weighs 40 N. Find the coefficient of kinetic friction between the box and the ...
Friday, April 5, 2013 at 1:03am

physics
how long 1.2kw electric kettle take to heat 0.8kg of water from 20c to 100c?
Thursday, April 4, 2013 at 11:46pm

Physics
The ski slopes at Bluebird Mountain make use of tow ropes to transport snowboarders and skiers to the summit of the hill. One of the tow ropes is powered by a 22-kW motor which pulls skiers along an icy incline of 14° at a constant speed. Suppose that 18 skiers with an ...
Thursday, April 4, 2013 at 11:46pm

Physics
A bat flying in a cave emits a sound and receives its echo 0.1 s later. Show that it's distance from the cave wall is 19 m.
Thursday, April 4, 2013 at 11:12pm

physics
Three different forces produce the same displacement: the vector Delta(r) starts at the left edge of your computer monitor and the tip points to the right edge of your monitor in a horizontal orientation. The first force has a magnitude of 10 N and it is pointing straight up, ...
Thursday, April 4, 2013 at 10:54pm

physics
An electron is accelerated from rest through a potential difference that has a magnitude of 2.90 × 107 V. The mass of the electron is 9.11 × 10-31 kg, and the negative charge of the electron has a magnitude of 1.60 × 10-19 C. (a) What is the relativistic ...
Thursday, April 4, 2013 at 10:06pm

PHYSICS
Light is shining perpendicularly on the surface of the earth with an intensity of 680 W/m2. Assuming that all the photons in the light have the same wavelength (in vacuum) of 478 nm, determine the number of photons per second per square meter that reach the earth.
Thursday, April 4, 2013 at 10:05pm

physics
A plastic rod has been bent into a circle of radius R = 8.80 cm. It has a charge Q1 = +4.60 pC uniformly distributed along one-quarter of its circumference and a charge Q2 = -6Q1 uniformly distributed along the rest of the circumference. Take V = 0 at infinity. (a) What is the...
Thursday, April 4, 2013 at 9:35pm

physics
Four acrobats of mass 61.0 kg, 68.0 kg, 62.0 kg, and 55.0 kg form a human tower, with each acrobat standing on the shoulders of another acrobat. The 61.0-kg acrobat is at the bottom of the tower. If the area of each of the 61.0-kg acrobat's shoes is 370 cm2, what average ...
Thursday, April 4, 2013 at 9:26pm

physics
A sled is accelerating down a hill at a rate of 1 m/s2 . If the mass of the sled is suddenly cut in half and the net force on the sled is doubled, what is the acceleration of the sled?
Thursday, April 4, 2013 at 9:10pm

Physics
A positively charged particle of mass 5.60 10-8 kg is traveling due east with a speed of 60 m/s and enters a 0.49-T uniform magnetic field. The particle moves through one-quarter of a circle in a time of 1.20 10-3 s, at which time it leaves the field heading due south. All ...
Thursday, April 4, 2013 at 8:56pm

Physics
A compact disk rotates from rest to 500 rev/min. in 5.5s. a) What is the angular acceleration assuming it is constant. b) How many revolutions does the disk make in 5.5 s. c) How far does a point on the rim 6 cm from the center of the disk traveling during the 5.5 s.
Thursday, April 4, 2013 at 7:58pm

Physics
An electric dipole (any pair of oppositely charge point particles) lies on the x-axis, consisting of a - 2.5nC charge at x = -10 cm, and a +2.5nC charge at x=10cm. Find the electric field (a) on the x-axis, at the point (20,0) and (b) on the y-axis, at point (0,10).
Thursday, April 4, 2013 at 6:04pm

Physics
A 2.0-ohm resistor is connected in series with a 20.0-V battery and a three-branch parallel network with branches whose resistances are 8.0 ohms each. Ignoring the battery's internal resistance, what is the current in the battery?
Thursday, April 4, 2013 at 5:17pm

physics
A man of mass 78.5 kg walks down the aisle of an airplane at a speed of 1.40 m/s in the forward direction while the plane moves at a speed of 320 m/s relative to the earth. (a) Find the man's kinetic energy relative to the plane. (b) Find the man's kinetic energy ...
Thursday, April 4, 2013 at 5:13pm

Physics
The temperature of an object is raised by 90ºC. This is equivalent to what increase in its absolute temperature?
Thursday, April 4, 2013 at 5:12pm

Physics
A supersonic aircraft produces a shock wave that describes a 30° cone. What happens to the angle of the cone as the aircraft travels faster?
Thursday, April 4, 2013 at 5:04pm

Physics
I am trying to help my step son who missed half of physics class due to a funeral. A laser beam is being shot through two different materials that have been stuck together. if theta 1 = 65.5 and theta 2 = 49.8 what is the index of refraction? (I got 1.2 which is correct) but ...
Thursday, April 4, 2013 at 3:55pm

Physics
A laser beam is being shot through two different materials that have been stuck together. if theta 1 = 65.5 and theta 2 = 49.8 what is the index of refraction? (I got 1.2 which is correct) but cant get part 2 PART 2~ If the index of refraction of n3 is 3.6, what is the final ...
Thursday, April 4, 2013 at 3:49pm

Physics
For safety in climbing, a mountaineer uses a nylon rope that is 55 m long and 0.9 cm in diameter. When supporting a 88-kg climber, the rope elongates 1.4 m. Find its Young's modulus.
Thursday, April 4, 2013 at 3:48pm

physics
A window washer is standing on a scaffold supported by a vertical rope at each end. The scaffold weighs 192 N and is 3.4 m long. What is the tension in each rope when the 708-N worker stands 2.40 m from one end? Smaller tension: ___N Larger tension: ___N
Thursday, April 4, 2013 at 2:58pm

Physics
An electron has a kinetic energy of 7.00 10-17 J. It moves on a circular path that is perpendicular to a uniform magnetic field of magnitude 4.40 10-5 T. Determine the radius of the path?
Thursday, April 4, 2013 at 2:31pm

physics
a toy moves on a horizontal surface with a speed of 3m/s.it makes 8 turns in 5 seconds,whats the diameter of the wheel?
Thursday, April 4, 2013 at 1:24pm

physics
A positively charged particle of mass 5.20 10-8 kg is traveling due east with a speed of 30 m/s and enters a 0.37-T uniform magnetic field. The particle moves through one-quarter of a circle in a time of 4.20 10-3 s, at which time it leaves the field heading due south. All ...
Thursday, April 4, 2013 at 12:33pm

physics
In the operating room, anesthesiologists use mass spectrometers to monitor the respiratory gases of patients undergoing surgery. One gas that is often monitored is the anesthetic isoflurane (molecular mass = 3.06 10-25 kg). In a spectrometer, a singly ionized molecule of ...
Thursday, April 4, 2013 at 12:29pm

physics
The ion source in a mass spectrometer produces both triply and quadruply ionized species, X3+ and X4+. The difference in mass between these species is too small to be detected. Both species are accelerated through the same electric potential difference, and both experience the...
Thursday, April 4, 2013 at 12:24pm

physics
a cannon with a mass of 1200 kilograms is positioned at the edge of a cliff where it fires a 100 kilogram cannonball horizontally. The cannonballs initial speed is 35 meters per second. What is the recoil of speed of the cannon.
Thursday, April 4, 2013 at 11:15am

Physics - Electricity
Three resistors (15, 20, 25 ohms in this order) are connected to a 13-V battery . The internal resistance of the battery is negligible. What is the voltage difference across the 20-Ω resistance?
Thursday, April 4, 2013 at 11:06am

physics
50+kg+ice+cube+slides+without+friction+up+and+down+a+30°+slope.+The+ice+cube+is+pressed+against+a+spring+at+the+bottom+of+the+slope,+compressing+the+spring+10cm+.The+spring+constant+is+25Nm.+When+the+ice+cube+is+released,what+distance+w&#...
Thursday, April 4, 2013 at 9:25am

Physics
Nicole throws a ball straight up.Chad watches the ball from a window 5meters above the point where Nicole released it . The ball passes Chad on the on the way up, and it has a speed of 10m/s as it passes him on the way back down.Determine how fast Nicole threw the ball upwards
Thursday, April 4, 2013 at 6:43am

physics
A man fires a rock of a slingshot directly upward.The rock has an initial velocity of 15m/s.How long will it take for the rock to return to the level he fired it at?
Thursday, April 4, 2013 at 4:06am

physics
the sounds of a cricket gets stronger as you get closer to it. if you get twice as close, how much louder will the sound be?
Thursday, April 4, 2013 at 1:14am

Physics
A long, narrow rectangular loop of wire is moving toward the bottom of the page with a speed of 0.021 m/s (see the drawing). The loop is leaving a region in which a 2.7 T magnetic field exists; the magnetic field outside this region is zero. During a time of 3.0 s, what is the...
Thursday, April 4, 2013 at 12:48am

physics
A woman is 1.6 m tall and has a mass of 47 kg. She moves past an observer with the direction of the motion parallel to her height. The observer measures her relativistic momentum to have a magnitude of 2.2 × 1010 kg·m/s. What does the observer measure for her height?
Thursday, April 4, 2013 at 12:27am

Physics
The magnification of an object 2km tall where placed in 150m in front of a plane mirror is ?
Thursday, April 4, 2013 at 12:16am

physics
A large building has an inclined roof. The length of the roof is 69.5 m and the angle of the roof is 18.0° below horizontal. A worker on the roof lets go of a hammer from the peak of the roof. Starting from rest, it slides down the entire length of the roof with a constant...
Wednesday, April 3, 2013 at 10:49pm

Physics
a 2.0 kg block moving at 8 m/s on a frictionless surface collides elastically with a block at rest. The first block moves in the same direction at 2 m/s. What is the second block's mass?
Wednesday, April 3, 2013 at 10:10pm

PHYSICS
A woman is 1.6 m tall and has a mass of 47 kg. She moves past an observer with the direction of the motion parallel to her height. The observer measures her relativistic momentum to have a magnitude of 2.2 × 1010 kg·m/s. What does the observer measure for her height?
Wednesday, April 3, 2013 at 9:59pm

physics
A 1.2kg object is placed on a frictionless table and is attached to a hanging mass using a light string over a frictionless pulley in a fletcher's trolley arrangement. The 1.20kg object accelerates along the table at 2.31m/s while the hanging object accelerates down at the...
Wednesday, April 3, 2013 at 7:53pm

physics
Romeo is trying to climb a ladder placed 3 meters away from a 4 meter high tower where Juliet is stuck. He weighs 110 kg, the ladder weighs 25 kg. Can Romeo climb to the top of the ladder? If so, can he bring Juliet back down with him?
Wednesday, April 3, 2013 at 6:26pm

physics
A solid steel cylinder is standing (on one of its ends) vertically on the floor. The length of the cylinder is 3.4 m and its radius is 58 cm. When an object is placed on top of the cylinder, the cylinder compresses by an amount of 5.9 10-7 m. What is the weight of the object?
Wednesday, April 3, 2013 at 6:16pm

Physics
What is the minimum height you would have to place a solid ball of mass M and radius R (I=2MR^2/5) on a hill in order for the ball to make it completely around a circular loop at the bottom of the hill? The diameter of the loop is D. Assume the ball rolls without slipping.
Wednesday, April 3, 2013 at 6:13pm

conceptual physics
If you mix a container of water in which the temperatures are 20 degrees Celsius and 24 degrees Celsius what would the temperature result be?
Wednesday, April 3, 2013 at 5:30pm

physics
Generally speaking, what is the distance between the oscillator and the wave stopper necessary to produce a standing wave?
Wednesday, April 3, 2013 at 5:01pm

physics
A copper cube, 0.31 m on a side, is subjected to two shearing forces, each which has a magnitude F = 6.40 106 N (see the drawing). Find the angle θ (in degrees), which is one measure of how the shape of the block has been altered by shear deformation.
Wednesday, April 3, 2013 at 5:01pm

Quantum Physics
Suppose a particle has wavefunction ψ(x,t=0)=Ae^(−x^2/l^2). What is the average value (expectation value) of p, <p>, for this state at t=0?
Wednesday, April 3, 2013 at 2:49pm

Quantum Physics
Suppose we have a particle in 1-dimension, with wavefunction Ae^(−|x|/2d). What is the probability to find the particle in the interval [0,d]?
Wednesday, April 3, 2013 at 2:44pm

Quantum Physics
The ground state wavefunction for a particle in a shallow potential well in 1 dimension is of the form: Ae^(−|x|/2d). Given that the particle must be found somewhere in the range x∈[−∞,∞], the born rule then places a constraint on the modulus of A...
Wednesday, April 3, 2013 at 2:41pm

physics
2 balss,one of iron and the other of aluminium,will experience the same upthrust, when dipped in water when both have equal what?
Wednesday, April 3, 2013 at 12:23pm

physics
A 5.11-kg pendulum bob, at a height of 0.730 m above the floor, is released and swings down to the ground where it collides elastically with a 2.29 kg block initially at rest. The block then slides up a 31.0° incline. Find how high up the incline the block will slide if (a...
Wednesday, April 3, 2013 at 12:23pm

physics
Find the outside surface area. Note that the containter has a top. (Assume a = 1.95 in, b = 1.35 in, c = 1.3 in, d = 1.25 in, and e = 2 in.)
Wednesday, April 3, 2013 at 6:51am

physics
An elevator was design to transport 13 passenger between floor of a ten story building. The unloaded elevator car weighs 1050kg. Assuming tha the average passengers weighs 70kg,determine the weight of the counter weight.
Wednesday, April 3, 2013 at 1:57am

Physics
Find the density of a 5.8- solid cylinder that is 15 cm tall with a radius of 5.0 .
Wednesday, April 3, 2013 at 12:59am

college physics
a tennis ball is thrown straight up with an initial velocity of 22.5 m/s. it is caught at the same distance above the ground. a). how long does it take to reach its maximum height? b). how high does the ball rise? c). at what speed does it hit the ground? d). what total length...
Tuesday, April 2, 2013 at 11:53pm

physics
c). at what speed does it hit the ground? d). what total length of time is the ball in the air
Tuesday, April 2, 2013 at 11:33pm

Physics 2
Light with λ = 530 nm passes through a single slit and then illuminates a screen 9.0 m away. If the distance on the screen from the first dark fringe to the center of the interference pattern is 3.20 mm, what is the width of the slit?
Tuesday, April 2, 2013 at 11:27pm

Physics
Three forces act on an object at the same time. F1 = 100. N at 30.0degrees north of east, F2 = 200. N at 45.0degrees north of west, and F3 = 100. N at 30.0degrees east of south. What are the magnitudes and direction of both the resultant force and equilibrant force?
Tuesday, April 2, 2013 at 9:16pm

Physics
Three forces act on an object at the same time. F1 = 10.0 N 50.0degrees north of east, F2 = 15.0 N 25.0degrees south of west, and F3 = 15.0 N 38.0degrees east of south. What is the magnitude and direction of the net force?
Tuesday, April 2, 2013 at 9:12pm

Physics
You are standing on a beach and 5 wave crests land on shore in 50 seconds. Each wave is 32m apart. Find Frequency, period, wavelength and speed.
Tuesday, April 2, 2013 at 9:03pm

Physics
The earth's Field is Roughly equivalent to an axial centered dipole. Find the vertical rate of change of the vertical component of the earth's field in gammas/foot here at flagstaff. Given" vertical component of earth's magnetic field at flagstaff is equal to ...
Tuesday, April 2, 2013 at 9:00pm

physics
7. No work is done by gravity on a bowling ball resting or moving on a bowling alley because the force of gravity on the ball acts perpendicular to the surface. But on an incline, the force of gravity has a vector component parallel to the alley. Discuss the two ways this ...
Tuesday, April 2, 2013 at 8:22pm

Physics
A force of 2000N is used to push a box up am inclined plane that is 15m long. If the 100 kg box is raised to a height of 8m,how much work is done against friction ?let g=10m/s^2.
Tuesday, April 2, 2013 at 7:39pm

Physics
The electric field lines surrounding three charges are shown in the figure below. The center charge is q2 = -15.9 µC.
Tuesday, April 2, 2013 at 7:33pm

Physics
A spring with a spring constant of 35.0 N/m is attached to diﬀerent masses, and the system is set in motion. What is the period for a mass of 34 g? Answer in units of s
Tuesday, April 2, 2013 at 7:19pm

Physics
A constant torque of 22.9 N·m is applied to a grindstone whose moment of inertia is 0.168 kg·m2. Using energy principles, and neglecting friction, find the angular speed after the grindstone has made 17.1 rev, assuming it started from rest. Answer in units of rev/s
Tuesday, April 2, 2013 at 6:18pm

physics
A uniform, 264-N rod that is 2.05 m long carries a 225-N weight at its right end and an unknown weight W toward the left end. When W is placed 47.9 cm from the left end of the rod, the system just balances horizontally when the fulcrum is located 82.7 cm from the right end. ...
Tuesday, April 2, 2013 at 4:35pm

physics
A 75.0 kN truck is parked in the middle of a 20.0 m long bridge. How much force must each end of the bridge exert to support the truck?
Tuesday, April 2, 2013 at 4:26pm

Physics
An iron railroad track 1000 feet long is at a temperature of 0 oC. How much does it expand when heated to 33 oC?
Tuesday, April 2, 2013 at 3:35pm

Physics
What is the frequency of a wave that has a period of 5.0 seconds?
Tuesday, April 2, 2013 at 2:32pm

Physics
What is the wavelength of a 512 Hz sound wave in 20 degree C air?
Tuesday, April 2, 2013 at 2:29pm

Physics
Jill screams and hears her echo 4.4 seconds later. How far from the canyon wall is she if the air temperature is 25 degree C?
Tuesday, April 2, 2013 at 2:18pm

Physics
Two lenses are in contact. One of the lenses has a focal length of +10.0cm when used alone. When the two are in combination, an object 20cm away from the lenses forms a real image 40cm away from the lenses. What is the focal length? I am not sure how to approach this problem. ...
Tuesday, April 2, 2013 at 2:18pm

physics
A rocket ship at rest in space gives a short blast of its engine, firing 26 kg of exhaust gas out the back end with an average velocity of 182 m/s. What is the change in momentum of the rocket during this blast?
Tuesday, April 2, 2013 at 1:38pm

Physics
One way to determine the distance to the moon is to bounce a laser beam off a mirror on its surface. How far away is the moon if it takes 2.56 seconds for the laser to "echo" off the moon?
Tuesday, April 2, 2013 at 1:23pm

Physics
Jill screams and hears her echo 4.4 seconds later. How far from the canyon wall is she if the air temperature is 25 degree C?
Tuesday, April 2, 2013 at 1:20pm

Physics
Joe stands 150 m from the edge of a canyon wall. How long will it take him to hear his echo if the air temperature is 250 degree C?
Tuesday, April 2, 2013 at 1:17pm

Physics
What is the wavelength of a 512 Hz sound wave in 20 degree C air?
Tuesday, April 2, 2013 at 1:12pm

Physics
The coil in the figure below contains 425 turns and has an area per turn of 3.00 10-3 m2. The magnetic field is 0.21 T, and the current in the coil is 0.27 A. A brake shoe is pressed perpendicularly against the shaft to keep the coil from turning. The coefficient of static ...
Tuesday, April 2, 2013 at 11:36am

Physics
Find the frequency of a sound wave moving in air at room temperature (20.0) with a wavelength of 0.667 m. Is the formula F=1/T?
Tuesday, April 2, 2013 at 11:27am

Physics
A player kicks a soccer ball from ground level and sends it flying at an angle of 30 degrees at a speed of 26 m/s. How far did the ball travel before it hit the ground? Round the answer to the nearest meter.
Tuesday, April 2, 2013 at 11:02am

physics
A space aircraft is launched straight up. The aircraft motor provides a constant acceleration for 10seconds, then the motor stops. The aircraft's altitude 15seconds after launch is 2km. Ignore air friction. Determine (i) the acceleration, (ii)the maximum speed reached in ...
Tuesday, April 2, 2013 at 9:05am

Physics
A plane flies horizontally at constant ground speed v=720km/h. The pilot is informed by an air traffic controller that he must immediately change his direction of flight while keeping the same altitude. The pilot performs a turning maneuver by rolling the plane to a banked ...
Tuesday, April 2, 2013 at 9:00am

Physics
A helium-4 atom falls from a height h into a tank of gaseous helium atoms at 300 K. What is h in meters if the temperature of the helium atoms remains at 300 K after the falling atom enters the tank? Details and assumptions The acceleration of gravity is −9.8 m/s2. As ...
Tuesday, April 2, 2013 at 8:59am

Physics
Mars has a mass of about 6.09x10^23 kg and it's moon Phobos has a mass of about 9.4 x10^15N how far apart are mars and Phobos? The value of the grav constant is 6.673 x10^-11 answer in units of N
Tuesday, April 2, 2013 at 8:00am

physics
Find modulus,Direction cosines,Unit vectors of (1)4a-2b+c,(2)a-7b+5c,(3)4a-3b+c.
Tuesday, April 2, 2013 at 7:42am

physics
block 1 has mass m1 = 480 g, block 2 has mass m2 = 540 g, and the pulley is on a frictionless horizontal axle and has radius R = 5.2 cm. When released from rest, block 2 falls 76 cm in 5.2 s (without the cord slipping on the pulley). What is the pulley's rotational inertia...
Tuesday, April 2, 2013 at 5:30am

physics
You and your friend, both of mass 70 kg, are playing catch with a frisbee on frictionless ice. Initially, you are both at rest. You throw a 0.175 kg frisbee at 10 m/s horizontally at your friend, who catches it. After they catch the frisbee, what is the relative velocity ...
Tuesday, April 2, 2013 at 4:13am

physics...
A kayaker paddles due north at 2 m/s. The river the kayaker is paddling in flows towards the east at 1 m/s. After 5 seconds of paddling, how far is the kayaker from where she started in m?
Tuesday, April 2, 2013 at 4:09am

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