Tuesday
September 1, 2015

Homework Help: Science: Physics

Recent Homework Questions About Physics

Physics
An atom is ionized so that it has only one electron. When the electron drops from the n = 6 shell to the n = 1 shell, an X-ray of wavelength 193.76 pm is emitted. What is the atomic number?
Wednesday, August 12, 2015 by Julie

physics
A bus accelerates at 2.4 m/s2 from rest for 10 s. It then travels at constant speed for 25 s, after which it slows to a stop with an acceleration of magnitude 1.5 m/s2. (a) What is the total distance that the bus travels? (b) What was its average velocity? If possible, could ...
Wednesday, August 12, 2015 by nico

physics
A bird watcher meanders through the woods, walking 0.544 km due east, 0.925 km due south, and 3.58 km in a direction 17.3 ° north of west. The time required for this trip is 1.957 h. Determine the magnitudes of the bird watcher's (a) displacement and (b) average velocity.
Wednesday, August 12, 2015 by bill

physics
The person in the drawing is standing on crutches. Assume that the force exerted on each crutch by the ground is directed along the crutch, as the force vectors in the drawing indicate. If the coefficient of static friction between a crutch and the ground is 0.793, determine ...
Wednesday, August 12, 2015 by ben

physics
The drawing shows a wire tooth brace used by orthodontists. The top-most tooth is protruding slightly, and the tension in the wire exerts two forces, and , on this tooth in order to bring it back into alignment. If the forces have the same magnitude of 19.4 N, what is the ...
Wednesday, August 12, 2015 by ben

physics
A car (m = 1870 kg) is parked on a road that rises 12.1 ° above the horizontal. What are the magnitudes of (a) the normal force and (b) the static frictional force that the ground exerts on the tires?
Wednesday, August 12, 2015 by kat

physics
A 15.5-kg sled is being pulled across a horizontal surface at a constant velocity. The pulling force has a magnitude of 76.7 N and is directed at an angle of 27 ° above the horizontal. Determine the coefficient of kinetic friction.
Wednesday, August 12, 2015 by sam

physics
A 72.2-kg person stands on a scale in an elevator. What is the apparent weight when the elevator is (a) accelerating upward with an acceleration of 1.53 m/s2, (b) moving upward at a constant speed, and (c) accelerating downward with an acceleration of 1.44 m/s2?
Wednesday, August 12, 2015 by ben

physics
Two point charges q1 = q2 = 2μC are fixed at x1 = + 3 and x2 = – 3. A third particle of mass 1 g and charge q3 = – 4 μC are released from rest at y = 4.0. Find the speed of the particle as it reaches the origin. q1= q q2= -q x θ
Wednesday, August 12, 2015 by sophie moagi

physics
A 10 μC charge of mass 20 g, initially at rest at x = - 1 m in a constant electric field E = 2000 V/m is released from rest. What is its speed at x = 5 m?
Wednesday, August 12, 2015 by sophie moagi

physics
A model rocket blasts off from the ground, rising straight upward with a constant acceleration that has a magnitude of 87.9 m/s2 for 1.51 seconds, at which point its fuel abruptly runs out. Air resistance has no effect on its flight. What maximum altitude (above the ground) ...
Wednesday, August 12, 2015 by james

Physics
On August 12, 1987, Alessandro Andrei set a world record in the shot put with a throw of 22.9m. What was the initial speed of the shot if he released it at a height of 2.10m and threw it at an angle of 38 degrees above the horizontal?
Wednesday, August 12, 2015 by Cassie

Physics
helicopter flies over the arctic ice pack at a constant altitude, towing an airborne 108-kg laser sensor which measures the thickness of the ice (see the drawing). The helicopter and the sensor move only in the horizontal direction and have a horizontal acceleration of ...
Wednesday, August 12, 2015 by Ben

Physics
A model rocket blasts off from the ground, rising straight upward with a constant acceleration that has a magnitude of 76.7 m/s2 for 1.89 seconds, at which point its fuel abruptly runs out. Air resistance has no effect on its flight. What maximum altitude (above the ground) ...
Wednesday, August 12, 2015 by Georgia

physics
Two blocks of masses is m and 2m are held in the equilibrium on a frictionless incline. In terms of m and x, find the magnitude of the tension t1 in the upper cord and the magnitude of the tension t2 in the lower cord connecting two blocks.
Tuesday, August 11, 2015 by Maria

physics
Determine the minimum size of a mirror that a lady 1.2m tall will buy to be able to see her full height if her eyes are placed 6cm from the top of her head and also determine how high the mirror must be place from d floor
Tuesday, August 11, 2015 by adaga

Physics
A tourist being chased by an angry bear is running in a straight line toward his car at a speed of 6.54 m/s. The car is a distance d away. The bear is 26.0 m behind the tourist and running at 10.4 m/s. The tourist reaches the car safely. What is the maximum possible value for d?
Tuesday, August 11, 2015 by Ben

physics
Determine the minimum size of a mirror that a lady 1.2m tall will buy to be able to see her full height if her eyes are placed 6cm from the top of her head
Tuesday, August 11, 2015 by adaga

Physics
Which one of the following actions would make the maxima in the interference pattern from a grating move closer together? A.Increasing the distance to the screen. B.Increasing the number of lines per length. C.Decreasing the number of lines per length. D.Decreasing the ...
Tuesday, August 11, 2015 by Thomas

physics
A bucket of water with a mass of 20.0 kg is being pulled up from a well with a single massless rope. If the tension in the rope is 200 N, calculate the acceleration of the bucket.
Tuesday, August 11, 2015 by lol

Physics
What is the speed of a geosynchronous satellite on Earth?
Tuesday, August 11, 2015 by Yoyo

physics
differentiate between law of paralleogram and resolution of component of force.
Tuesday, August 11, 2015 by amit kumar das

Physics
A 10 g dart traveling at 400 m/s sticks into a 10 kg, 1 m wide door at the edge opposite the hinge causing the door to swing open. What is the angular velocity of the door immediately after impact?
Tuesday, August 11, 2015 by Yoyo

Physics
The rotational inertia of a collapsing star changes to one third its initial value while conserving angular momentum. What is the ratio of the new rotational kinetic energy to the initial kinetic energy?
Tuesday, August 11, 2015 by Yoyo

Physics
body of mass 0.3 kg is taken up a client Plains of length and height 5 metres and then allowed to slide down to the bottom again the coefficient of friction between the body and the plane is 0.15 what is the work done by gravitational force over round trip?
Tuesday, August 11, 2015 by Pushpinder Singh

physics
What is the magnitude of the average acceleration of a skier who, starting from rest, reaches a speed of 10.5 m/s when going down a slope for 3.18 s?
Tuesday, August 11, 2015 by james

physics
1) a wire of length 1m has a resistance of 2 ohm.obtain the resistance if specific resistance is double,diameter is double and the length is made three times of the first.
Tuesday, August 11, 2015 by Rose

physics
A hot-air balloon is rising upward with a constant speed of 3.29 m/s. When the balloon is 3.38 m above the ground, the balloonist accidentally drops a compass over the side of the balloon. How much time elapses before the compass hits the ground?
Tuesday, August 11, 2015 by james

Physics
he drawing shows two planes each dropping an empty fuel tank. At the moment of release each plane has the same speed of 185 m/s, and each tank is at the same height of 3.62 km above the ground. Although the speeds are the same, the velocities are different at the instant of ...
Tuesday, August 11, 2015 by Cassie

Physics
Please what is Empirical Temperaturee
Tuesday, August 11, 2015 by badmus

physics
a sled is moving up a slope that makes an angle θ of 5.00◦ with respect to the horizontal. The coefficient of kinetic friction between the sled and the snow is μk = 0.0500. What is the magnitude of the acceleration of the sled as it moves up the slope?
Tuesday, August 11, 2015 by anonymous

physics
The drawing shows a skateboarder moving at 6.87 m/s along a horizontal section of a track that is slanted upward by 51.9 ° above the horizontal at its end, which is 0.616 m above the ground. When she leaves the track, she follows the characteristic path of projectile ...
Tuesday, August 11, 2015 by anonymous

physics
A person is trying to judge whether a picture (mass = 1.64 kg) is properly positioned by temporarily pressing it against a wall. The pressing force is perpendicular to the wall. The coefficient of static friction between the picture and the wall is 0.700. What is the minimum ...
Tuesday, August 11, 2015 by anonymous

PHYSICS
The temperature of the cosmic background radiation is measured to be 2.7 K. What is the wavelength of the peak in the spectral distribution at this temperature? What frequency corresponds to this wavelength?
Monday, August 10, 2015 by Julie

PHYSICS
Suppose that at least 13.0 eV is needed to free an electron from a particular element, i.e., to ionize the atom. What is the lowest frequency photon which can accomplish this? And, what is the corresponding wavelength for that photon? Give frequency for answer 1 and wavelength...
Monday, August 10, 2015 by Julie

Physics
A torque of 32Nm is applied to a wheel, which causes it to accelerate at 25 rad/s2. What is the rotational moment of inertia of the wheel? I got 1.28kg/m^2. Is this correct?
Monday, August 10, 2015 by Yoyo

physics
A dog runs west for 20m then North for 15m. What is the resultant displacement of the dog graphically and by calculations
Monday, August 10, 2015 by sfundo

physics
a plane travelling at 200.0m/s braked to a stop in 6.2s. what was its acceleration?
Monday, August 10, 2015 by Anonymous

engineering physics 1-science
A crate of mass m(=32 kg) rides on the bed of a truck attached by a cord to the back of the cab . The cord can withstand a maximum tension of 68N before breaking. Neglecting friction between the crate and the truck bed, find the maximum acceleration the truck can have before ...
Sunday, August 9, 2015 by Endes Nalabaw

Physics
A spaceship is on a straight-line path between the Earth and the Moon. At what distance from Earth is the net gravitational pull on the probe from the Earth and the moon zero? Mass of Earth = 6×10^24 kg. Mass of Moon = 7×10^22 kg. Can someone please confirm if my ...
Sunday, August 9, 2015 by Yoyo

Physics
A torque of 32Nm is applied to a wheel, which causes it to accelerate at 25 rad/s2. What is the rotational moment of inertia of the wheel? I got 1.28kg/m^2. Is this correct?
Sunday, August 9, 2015 by Yoyo

physics
light from the sun travels 1.5x10km to reach the earth .how long does it journey take in minutes?
Sunday, August 9, 2015 by rob

physics
A 33 tonnes jet airline has 4 engines,each producing a nearly constant thrust of 165kN during the takeoff roll.Determine the length of the runway required if the takeoff speed is 320km/h.Neglect air and rolling resistance.
Sunday, August 9, 2015 by olivia (pls help!!)

physics
a projectile is fired at an angle of 27 above the horizontal from the top of a cliff 500 ft high. The initial speed of projectile is 1670 ft/s. How far will it move horizontally before hitting the level ground at the base of the cliff?
Sunday, August 9, 2015 by vien

physics
A 50.9-kg crate rests on a level floor at a shipping dock. The coefficients of static and kinetic friction are 0.526 and 0.311, respectively. What horizontal pushing force is required to (a) just start the crate moving and (b) slide the crate across the dock at a constant speed?
Sunday, August 9, 2015 by anonymous

physics
A golfer hits a shot to a green that is elevated 2.70 m above the point where the ball is struck. The ball leaves the club at a speed of 19.0 m/s at an angle of 36.0˚ above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air ...
Saturday, August 8, 2015 by anonymous

physics
Using the following conversion factors, determine the number of milliliters in a volume of 2.37 fluid ounces: 1 gallon (gal) = 128 oz., 3.785 x 10-3 cubic meters (m3) = 1 gal, 1 mL = 10-6 m3. I got an answer 7.09ml, but it's incorrect, so confused how to covert those factors
Saturday, August 8, 2015 by Jack

physics
A 50.9-kg crate rests on a level floor at a shipping dock. The coefficients of static and kinetic friction are 0.526 and 0.311, respectively. What horizontal pushing force is required to (a) just start the crate moving and (b) slide the crate across the dock at a constant speed?
Saturday, August 8, 2015 by anonymous

Physics
A lumberjack (mass = 104 kg) is standing at rest on one end of a floating log (mass = 234 kg) that is also at rest. The lumberjack runs to the other end of the log, attaining a velocity of +3.18 m/s relative to the shore, and then hops onto an identical floating log that is ...
Saturday, August 8, 2015 by Cassie

physics
A swimmer, capable of swimming at a speed of 1.81 m/s in still water (i.e., the swimmer can swim with a speed of 1.81 m/s relative to the water), starts to swim directly across a 2.29-km-wide river. However, the current is 1.31 m/s, and it carries the swimmer downstream. (a) ...
Saturday, August 8, 2015 by anonymous

physics
A golfer hits a shot to a green that is elevated 2.70 m above the point where the ball is struck. The ball leaves the club at a speed of 19.0 m/s at an angle of 36.0˚ above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air ...
Saturday, August 8, 2015 by anonymous

physics
damon,reiny,steve,ms sue.plz get a solution 2 my question please itz urgent!!!
Saturday, August 8, 2015 by edward

Physics
so i need to calculate the moment of inertia of the pulley and the angular acceleration of the pulley. mass A = 9kg Mass B = 15kg Inner pulley= Mass 3kg R= 6cm Outerpulley= mass 7kg R=12cm both are disks glued together. it is a composite pulley with two masses hanging. Mass A ...
Saturday, August 8, 2015 by john

physics
qustion(1):A rectangular face of a casting 250mmx100mm is to be machined on a sharper.if the average cuting speed is to be 20m/min and the feed is to be 2mm/stroke,calculate the time taken to machine the face of casting.allow 5mm overun at each end of the stroke. question(2):...
Saturday, August 8, 2015 by edward

Physics
A dog runs west for 20m then north for 15m. What is the resultant displacement of the dog graphically and by calculations?
Saturday, August 8, 2015 by Sfundo

Physics
Leila walks south for 20m and then west for 20m. What is her resultant displacement graphically?
Saturday, August 8, 2015 by Sfundo

Physics
Just reposting. A spaceship is on a straight-line path between the Earth and the Moon. At what distance from Earth is the net gravitational pull on the probe from the Earth and the moon zero? Mass of Earth = 6×10^24 kg. Mass of Moon = 7×10^22 kg. The distance from ...
Saturday, August 8, 2015 by Yoyo

Physics
Just reposting. A cricket ball rotates at 1800 rev/min as it travels through the space in a straight line at 160 km/hr. How many times does it revolve after traveling 20m? Can someone confirm with me if 13.5 revolutions in 20m is right. That's the answer i got to. If it&#...
Saturday, August 8, 2015 by Yoyo

physics
A proton with charge mass ratio of 108 C/kg is moving in a circular orbit in a uniform magnetic field of 0.5T .Calculate the frequency of revolution.
Saturday, August 8, 2015 by Simran

physics
A pole of infinite length is planted vertically on the ground. A stone is placed at a distance of 'd1' meters from the pole towards the right. A bird is sitting on the ground exactly in the middle of the pole and stone. The bird flies away towards the right in such a ...
Friday, August 7, 2015 by Anonymous

Physics
A spring streches by 3.90 cm when a 10g mass is hung from it. If a 25g mass attached to this spring oscillates in simple harmonic motion, calculate the period of the motion?
Friday, August 7, 2015 by Godwin

physics
An object undergoes simple harminic motion of amplitude A. Through what total distance does the object move during one complete cycle of its motion?
Friday, August 7, 2015 by Godwin

physics
a stone is thrown in such a manner that it would just hit a bird at the top of a tree and afterwards reach a maximum height double that of the tree . if at the moment of throwing the stone the bird flies away horizontally with constant velocity and the stone hits the bird ...
Friday, August 7, 2015 by prabhat

Physics
If a man weighs 900 N on the earth, what would he weigh on jupiter, where acceleration due to gravity is 25.9 m/s^2?
Friday, August 7, 2015 by Godwin

physics
a pin has a diameter of 0.005mm at its sharp end. calculate the pressure exerted when a force of 2.0N is applied to the pin.
Friday, August 7, 2015 by kongo

physics
a bullet of mass 20g is fired into a block of wood of mass 400g . if the bullut and wood move together with speed of 20ms-1 calclate(i) speed with the bullet hits the wood ii the kinetic energy lost iii state the energy changes involed
Friday, August 7, 2015 by kongo.

Physics
Suppose you wanted to be able to see astronauts on the moon. What is the smallest diameter of the objective lens required to resolve a 0.61 m object on the moon?
Friday, August 7, 2015 by Mary

Physics
Which one of the following actions would make the maxima in the interference pattern from a grating move closer together? Decreasing the frequency of the laser. Increasing the frequency of the laser. Increasing the number of lines per length. Increasing the wavelength of the ...
Friday, August 7, 2015 by Mary

Physics
A spaceship is on a straight-line path between the Earth and the Moon. At what distance from Earth is the net gravitational pull on the probe from the Earth and the moon zero? Mass of Earth = 6×10^24 kg. Mass of Moon = 7×10^22 kg. The distance from the sun to the ...
Friday, August 7, 2015 by Yoyo

Physics
A meter-long stick is balanced vertically on the ground. It is then made to fall with a gentle nudge. What is the speed of the end of the stick as it hits the floor? Assume the end on the floor does not slip. Treat the stick as a “thin rod.” Really need help with ...
Friday, August 7, 2015 by Yoyo

Physics
A torque of 32Nm is applied to a wheel, which causes it to accelerate at 25 rad/s2. What is the rotational moment of inertia of the wheel? I got 1.28kg/m^2.
Friday, August 7, 2015 by Yoyo

Physics
A cricket ball rotates at 1800 rev/min as it travels through the space in a straight line at 160 km/hr. How many times does it revolve after traveling 20m? Can someone confirm with me if 13.5 revolutions in 20m is right. That's the answer i got too. If it's wrong can ...
Friday, August 7, 2015 by Yoyo

physics
A puck is moving on an air hockey table. Relative to an x, y coordinate system at time t = 0 s, the x components of the puck's initial velocity and acceleration are v0x = +3.9 m/s and ax = +1.2 m/s2. The y components of the puck's initial velocity and acceleration are ...
Friday, August 7, 2015 by sarah

Physics
A 100 kg load is lowered by means of a cable with a downward acceleration of 5.0 m/s^2. What is the tension in the cable?
Friday, August 7, 2015 by Godwin

physics
Suppose a car is traveling at +15.0 m/s, and the driver sees a traffic light turn red. After 0.405 s has elapsed (the reaction time), the driver applies the brakes, and the car decelerates at 6.00 m/s2. What is the stopping distance of the car, as measured from the point where...
Friday, August 7, 2015 by sarah

physics
How many grams of Al2O3 are formed from 15L of O2 at 97.5kPa and at 21degree celcius.
Friday, August 7, 2015 by Alice

physics
(a) What is the magnitude of the average acceleration of a skier who, starting from rest, reaches a speed of 10.5 m/s when going down a slope for 3.18 s? (b) How far does the skier travel in this time?
Friday, August 7, 2015 by sarah

physics
A gas at 250K and 15atm has a molar volume smaller than calculated from perfect gas law Calculate: a) the compression factor under these conditions b) the molar volume of gas
Friday, August 7, 2015 by Alice

Physics
a 50 g marble is released from a height 1 m above the floor. Calculate its momentum just before hitting the ground
Friday, August 7, 2015 by Anonymous

physics
A 1000 kg car can accelerate from rest to a speed of 25 m/s in 10 s. What average power must the engine of car produce in order to cause this acceleration? Neglect friction losses
Friday, August 7, 2015 by Muqadas

Physics
A block is given an initial velocity of 5.00 m/s up a frictionless 20degree incline. How far up the incline does the block slide before coming to rest?
Thursday, August 6, 2015 by Godwin

Physics
A tugboat exacts a constant force of 5 000N on a ship moving at constant speed through a harbor. How much work does the tugboat do on the ship in a distance of 3.00 km?
Thursday, August 6, 2015 by Godwin

Physics
Monochromatic light of wavelength, λ is traveling in air. The light then strikes a thin film having an index of refraction n1 that is coating a material having an index of refraction n2. If n2 is larger than n1, what minimum film thickness will result in maximum ...
Thursday, August 6, 2015 by Julie

Physics
A ship travels 100 km due north on the first day of a voyage, 60 km north-east on the second day, and 120 km due east on the third day. Find the resultant displacement.
Thursday, August 6, 2015 by Godwin

physics
Two identical pellet guns are fired simultaneously from the edge of a cliff. These guns impart an initial speed of 44.7 m/s to each pellet. Gun A is fired straight upward, with the pellet going up and then falling back down, eventually hitting the ground beneath the cliff. Gun...
Thursday, August 6, 2015 by sarah

physics
A car is traveling at a constant speed of 25.5 m/s on a highway. At the instant this car passes an entrance ramp, a second car enters the highway from the ramp. The second car starts from rest and has a constant acceleration. What acceleration must it maintain, so that the two...
Thursday, August 6, 2015 by sarah

physics
A bicycle is rolling down a circular portion of a path; this portion of the path has a radius of 8.73 m. As the drawing illustrates, the angular displacement of the bicycle is θ = 0.979 rad. What is the angle (in radians) through which each bicycle wheel (radius = 0.320 m...
Wednesday, August 5, 2015 by paul

physics
Q: A block A of mass 0.5 kg can slide on a frictionless incline of angle 30o and length 0.8 m kept inside an elevator going up with uniform velocity 2m/s. Find the time taken by the block to slide down the length of the incline if it is released from the top of the incline. ...
Wednesday, August 5, 2015 by mohit

college. physics and chemistry and mathematics
An element crystalline in face centred cubic lattice. CCalculate the length of the side of the unit cell if the radius of atom is200pm
Wednesday, August 5, 2015 by nerswn narzary

Physics
A particle with a mass of 0.660 kg is attached to a horizontal spring with a force constant of 23.76 N/m. At the moment t = 0, the particle has its maximum speed of 15 m/s and is moving to the left. (Assume that the positive direction is to the right.) (a) Determine the ...
Wednesday, August 5, 2015 by Mark

Physics
The position of a particle is given by the expression x = 2.00 cos (6.00πt + π), where x is in meters and t is in seconds. (a) Determine the frequency. ______Hz (b) Determine period of the motion. ______s (c) Determine the amplitude of the motion. ______m (d) ...
Wednesday, August 5, 2015 by Mark

Physics
A fully loaded elevator weighing 2000 lbs accelerates upward from rest, attaining its rated velocity of 20 fps upon reaching a height of 25 ft. Solve for the tension on the cable lifting the elevator. What is the minimum required power of the lifting motor if 10% is allowed ...
Wednesday, August 5, 2015 by Aries

Physics
Calulate the acceleration of a 300,000kg jet on take when the thrust is equal to 120,000N. I used a = f/m to get 0.4m/s/s Tricky part. How long a runway is required for the plane to take off at a speed of 300km/h? Help?
Wednesday, August 5, 2015 by Roland

physics
A coil takes a current of 10.0 A and dissipates 1410 W when connected to a 230 V, 50 Hz sinusoidal supply. When another coil is connected in parallel with it, the total current taken from the supply is 20.0 A at a power factor of 0.866. Determine the current and the overall ...
Tuesday, August 4, 2015 by lolo

Physics
Calculate the angular momentum of a 1.75 kg ball rotating on the end of a thin string in a circle of radius 3.5 and an angular speed of 11 rad /s. Treat the ball as a point.
Tuesday, August 4, 2015 by Anonymous

Physics
A 1.00 kg glider attached to a spring with a spring constant of 40 N/m oscillates on a horizontal, frictionless air track. At t = 0 the glider is released from rest at x = -17 cm. Find the maximum value of the velocity in m/s.
Tuesday, August 4, 2015 by Anonymous

Physics
Two planets of mass 7 x 10^25 kg are release from rest 2.5 x 10^12 m apart. What is the speed of the planets when they are half this distance apart?
Tuesday, August 4, 2015 by Anonymous

Physics
A small fly of mass 0.25 g is caught in a spider’s web. The web vibrates predominately with a frequency of 5 Hz. Find the value of the spring constant.
Tuesday, August 4, 2015 by Anonymous

Physics
A 1.00 kg glider attached to a spring with a spring constant of 40 N/m oscillates on a horizontal, frictionless air track. At t = 0 the glider is released from rest at x = -17 cm. Find the maximum value of the velocity in m/s.
Tuesday, August 4, 2015 by Anonymous

Physics
Two planets of mass 7 x 10^25kg are released from rest 2.5 x 10^12 m apart. What is the speed of the planets when they are half this distance apart?
Tuesday, August 4, 2015 by Anonymous

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