Saturday
May 25, 2013

# Homework Help: Science: Physics

Physics
If the same shoe were dropped from a height of 40m, how many seconds would it take it to hit the floor?
Friday, May 17, 2013 at 3:56pm

World History
1. The purpose of American and European imperialism in the Pacific was mainly to gain. A. markets fro manufactured products B. coaling stations and naval bases C. sources of raw materials D. places for surplus population I said C. 2. The development of antiseptics during the ...
Friday, May 17, 2013 at 3:39pm

Physics
A circular plate of radius 0.5 m is placed perpendicular to the direction of the magnetic field of 0.5 Tesla. What is the change of flux in the plate if it rotates and its plane becomes parallel to the direction of the magnetic field?
Friday, May 17, 2013 at 2:08pm

physics
In a city grid, each block on the east-west streets is 100 meters long. Each block on the north-south streets is 20 meters long. A walker walks 4 blocks west and then 4 blocks south. How much father did the walker travel than the actual distance between the start and end ...
Friday, May 17, 2013 at 10:45am

physics
Q 4_1? 4_2? 4_3? plz help.
Friday, May 17, 2013 at 9:16am

physics
One day I decide I want to see how high I can throw a rock. I throw a rock straight up in the air and it has a speed of 30 m/s when it leaves my hand. I then realize this was foolish, as I need to get out of the way before the rock comes back down and hits me on the head. How ...
Friday, May 17, 2013 at 6:40am

physics
Two point charges +q=1 μC and −q=−1 μC with mass m=1 g are fixed at the positions ±r⃗ 0 with |r0|=1 m. The charges are released from rest at t=0. Find the time τ in seconds at which they collide. Hint: Can you do it without integrating ...
Friday, May 17, 2013 at 6:39am

physics
Two point charges +q=1 μC and −q=−1 μC with mass m=1 g are fixed at the positions ±r⃗ 0 with |r0|=1 m. The charges are released from rest at t=0. Find the time τ in seconds at which they collide. Hint: Can you do it without integrating ...
Friday, May 17, 2013 at 4:33am

Physics
A ball is fastened to one en of a 28 cm string, and the other end is held fixed to a support. The ball whirls in a horizontal circle. Find the speed of the ball in its circular path if the string makes an angle of 35 degrees to the vertical.
Thursday, May 16, 2013 at 10:50pm

physics
A load W=2 kN is applied vertically to joint C of truss ABCDE as indicated. You will use the method of joints to obtain the axial forces in the bars and reactions at the supports A, E .
Thursday, May 16, 2013 at 9:36pm

Physics
From a height of 30.5 , a 1.45 bird dives (from rest) into a small fish tank containing 49.0 of water. What is the maximum rise in temperature of the water if the bird gives it all of its mechanical energy?
Thursday, May 16, 2013 at 9:30pm

physics
A human cannonball is launched from a cannon at 26.4 m/s at 20.4 degrees above the horizontal. (Assume he/she lands in a net the same height as the cannon.) How high in the air does he/she go?
Thursday, May 16, 2013 at 7:48pm

Physics
Two point charges +q=1 ìC and −q=−1 ìC with mass m=1 g are fixed at the positions ±r ⃗ 0 with |r 0 |=1 m . The charges are released from rest at t=0 . Find the time ô in seconds at which they collide.
Thursday, May 16, 2013 at 7:17pm

Physics, Capacitance
What would be the capacitance of a ball the size of the sun, if a conducting material covered its entire surface (radius, R = 7108 m)?
Thursday, May 16, 2013 at 3:21pm

physics
A car with a mass of 1000kg is travelling at a constant velocity. The force from the engine is 200Newtons. Calculate the acceleration of the car using the formula f=ma. How long will it take this car to travel 0-60 mph (n.b. 1mph = 0.45m/s)
Thursday, May 16, 2013 at 2:40pm

physics
a 75-kilogram bicylcist coasts down a hill at a constant speed of 12 meters per second. what is the kinetic energyof the bicyclist?
Thursday, May 16, 2013 at 1:42pm

physics(HELP..)
A diatomic ideal gas is heated at constant volume until its pressure becomes 3 times.it is again heated at constant pressure until its volume is doubled.find the molar heat capacity for the whole process?
Thursday, May 16, 2013 at 3:49am

physics
A diatomic ideal gas is heated at constant volume until its pressure becomes 3 times.it is again heated at constant pressure until its volume is doubled.find the molar heat capacity for the whole process?
Thursday, May 16, 2013 at 3:49am

physics
A diatomic ideal gas is heated at constant volume until its pressure becomes 3 times.it is again heated at constant pressure until its volume is doubled.find the molar heat capacity for the whole process?
Thursday, May 16, 2013 at 3:46am

Physics
If the EMF produced in a wire is 0.88 volts and the wire moves perpendicular to a magnetic field of strength 0.075 newtons/amp·meter at a speed of 4.20 meters/second, what is the length of the wire in the magnetic field?
Thursday, May 16, 2013 at 1:22am

Physics
A frog is jumping around its pond. At some time t , the frog is in mid-jump and has a kinetic energy of 1 J and a momentum of magnitude 0.5 kg⋅m/s . What is the mass of the frog in kg?
Wednesday, May 15, 2013 at 11:05pm

Physics
Two point charges +q=1 ìC and −q=−1 ìC with mass m=1 g are fixed at the positions ±r ⃗ 0 with |r 0 |=1 m . The charges are released from rest at t=0 . Find the time ô in seconds at which they collide.
Wednesday, May 15, 2013 at 11:01pm

physics 11
a 4.00kg object traveling westward at 25.0m/s hits a 15.0kg object at rest. the 4.00kg object bounces eastward at 8.00m/s. what is the speed and direction of the 15.0kg object?
Wednesday, May 15, 2013 at 6:34pm

Physics
An open organ pipe of length 0.744411 m and a closed one of length 1.10545 m are sounded together. What beat frequency is generated by the first overtone of the closed pipe with the fundamental of the open pipe? The speed of sound is 340 m/s. Answer in units of Hz
Wednesday, May 15, 2013 at 4:39pm

Physics
When two tuning forks are stuck simultaneously, 3 beats per second are heard. The frequency of one fork is 510 Hz. A piece of wax is placed on the 510 Hz fork to lower its frequency slightly. If the beat frequency is increased, what is the correct frequency for the second fork...
Wednesday, May 15, 2013 at 4:38pm

physics
A runner dashes from the starting line (x=0) to a point 108 m away and then turns around and runs to a point 19 m away from the starting point in 23.4 seconds. To the nearest tenth of a m/s what is the average speed?
Wednesday, May 15, 2013 at 3:15pm

Physics
Jemima is sanding some floorboards with an electric sander which has a power rating of 360W. Jemima has the sander on for 45 minutes. The Sander is only 55% efficient. The electricity supplier charges 14.8p per kWh. What will be the cost of the 'wasted' energy? I know ...
Wednesday, May 15, 2013 at 1:21pm

physics
two lead spheres whose diameters are 20 cm and 2 cm are placed with centres 100 cm apart. Calculate the force of gravitation between them.(density of lead =11500 kg/m^3
Wednesday, May 15, 2013 at 10:02am

physics/chemistry(Thermodynamics)!!!!!helppppp!
In a certain chemical process,a lab technician supplies 254 j of heat to a system. At the same time,73 j of work are done on the system by iys surroundings.What is the increase in the internal energy of the system?
Wednesday, May 15, 2013 at 9:57am

Physics
A point charge of charge 1 mC and mass 100 g is attached to a non-conducting massless rod of length 10 cm. The other end of the rod is attached to a two-dimensional sheet with uniform charge density σ and the rod is free to rotate. The sheet is parallel to the y-z plane (...
Wednesday, May 15, 2013 at 5:33am

science-physics
A worker sits at one end of a 183-N uniform rod that is 2.80 m long. A weight of 107 N is placed at the other end of the rod. The rod is balanced when the pivot is 0.670 m from the worker. Calculate the weight of the worker
Wednesday, May 15, 2013 at 1:51am

Physics
How long is the sound wave if frequency is 320 Hz? Speed of sound =340 m/s
Wednesday, May 15, 2013 at 12:05am

Physics
A point charge of charge 1 mC and mass 100 g is attached to a non-conducting massless rod of length 10 cm. The other end of the rod is attached to a two-dimensional sheet with uniform charge density σ and the rod is free to rotate. The sheet is parallel to the y-z plane (...
Tuesday, May 14, 2013 at 11:40pm

physics
An organ pipe is 84 cm long and at a temperature of 20 degrees C. What is the fundamental (in Hertz) if the pipe is closed at one end thanks!
Tuesday, May 14, 2013 at 10:31pm

physics
A guitar string is 92 cm long and has a mass of 3.7 g. The length L from the bridge to the support post is 65 cm, and the string is under a tension of 570 N. What is the frequency of the fundamental tone thanks!
Tuesday, May 14, 2013 at 9:45pm

PHYSICS/CHEMISTRY
Can someone explain to me, what does Metastable isotope means? I already read the definitions on the internet but I really don't understand it. Thanks in advance.
Tuesday, May 14, 2013 at 9:22pm

physics
Two point charges +q=1 μC and −q=−1 μC with mass m=1 g are fixed at the positions ±r ⃗ 0 with |r 0|=1 m. The charges are released from rest at t=0. Find the time τ in seconds at which they collide.
Tuesday, May 14, 2013 at 9:03pm

physics
thus far in the course we have ignored that on the earths surface an object must have a slightly unbalanced force to rotate with the earth, pretending that the normal force precisely balances the objects weight. A student with a mass of 65.0kg stands at the equator. The radius...
Tuesday, May 14, 2013 at 8:05pm

physics
the space shuttle typically orbits 400 km above the earths surface. The earth has a mass of 5.98 * 10^24 kg and a radius of 6380km. A) How much would a 2000 kg part for the space station weigh when it has been lifted to that orbit in the shuttles cargo bay? B)Use your result ...
Tuesday, May 14, 2013 at 7:54pm

physics
A person takes a trip, driving with a constant speed of 92.5 km/h except for a 20.0 min rest stop. If the person's average speed is 71.2 km/h, how much time is spent on the trip and how far does the person travel?
Tuesday, May 14, 2013 at 7:49pm

Physics
A roller coaster has a mass of 425 kg. It sits at the top of a hill with height 66 m. If it drops from this hill, how fast is it going when it reaches the bottom? (Assume there is no air resistance or friction.)
Tuesday, May 14, 2013 at 4:40pm

physics
The convex lens of a copy machine has a focal length of 22.0 cm. A letter to be copied is placed 37.0 cm from the lens. (a) How far from the lens is the copy paper? (b) How much larger will the copy be?
Tuesday, May 14, 2013 at 3:23pm

physics
In order to clearly read a book 16 cm away, a farsighted girl needs an image to be 36 cm from her eyes. What focal length is needed for the lens in her eyeglasses?
Tuesday, May 14, 2013 at 3:22pm

physics
Camera lenses are described in terms of their focal length. A 50.0 mm lens has a focal length of 50.0 mm. (a) A camera with a 50 mm lens is focused on an object 4.0 m away. Locate the image. (b) A 980 mm lens is focused on an object 125 m away. Locate the image.
Tuesday, May 14, 2013 at 3:22pm

physics
A convex lens is needed to produce an image that is 0.70 times the size of the object and located 28 cm from the lens on the other side. What focal length should be specified?
Tuesday, May 14, 2013 at 3:22pm

physics
The speed of light in a certain piece of clear plastic is 1.95 108 m/s. A ray of light strikes the plastic at an angle of 21°. At what angle is the ray refracted?
Tuesday, May 14, 2013 at 3:21pm

physics
A ray of light in a tank of water has an angle of incidence of 23°. What is the angle of refraction in air? (Enter 0 if total internal reflection occurs.)
Tuesday, May 14, 2013 at 3:21pm

physics
he index of refraction of crown glass is 1.53 for violet light, and it is 1.51 for red light. (a) What is the speed of violet light in crown glass? (b) What is the speed of red light in crown glass?
Tuesday, May 14, 2013 at 3:20pm

physics
A diamond's index of refraction for red light, 656 nm, is 2.410, while that for blue light, 434 nm, is 2.450. Suppose white light is incident on the diamond at 32.2°. Find the angles of refraction for red and blue light. red light? blue light?
Tuesday, May 14, 2013 at 3:20pm

physics
A thick sheet of plastic, n = 1.500, is used as the side of an aquarium tank. Light reflected from a fish in the water has an angle of incidence of 30.0°. At what angle does the light enter the air?
Tuesday, May 14, 2013 at 3:19pm

physics
A beam of light strikes the flat, glass side of a water-filled aquarium at an angle of 37.5° to the normal. For glass, n = 1.50. (a) At what angle does the beam enter the glass? (b) At what angle does the beam enter the water?
Tuesday, May 14, 2013 at 3:19pm

Physics
The truss structure ABCD is loaded with a concentrated force P = 2 kN applied at a 45° angle at joint D as indicated in the figure. All bars in the truss have equal cross sectional area and are made of the same homogeneous linear elastic material. The dimensions are H=3 m ...
Tuesday, May 14, 2013 at 1:23pm

physics
A 12 g bullet is stopped in a block of wood (mw = 5.9 kg). The speed of the bullet- plus-wood combination immediately after the collision is 0.95 m/s. What was the original speed of the bullet? Answer in units of m/s
Tuesday, May 14, 2013 at 1:19pm

Physics helpp
Newtons 2nd law The force of earths gravity is about 10 N downward. Whats the acceleration of a 15kg backpack if lifted with a 15N force??
Tuesday, May 14, 2013 at 10:49am

science physics
1.) What is the Magnitude of the electrostatic force on a +5 C charge 1.75 m to the left of a -2.5 C charge? (show your work) 2.) In What direction does the force on the +5 C charge act? 3.)Calculate the magnitude of the electric field of the -2.5 C charge at the location of ...
Tuesday, May 14, 2013 at 10:42am

physics
What is the magnitude of the electrostatic force on a +5 C harge 1.75 m to the left of a -2.5 C Charge? (show your work)
Tuesday, May 14, 2013 at 10:38am

Physics
Newtons second law What net force acting on a 14kg wagon produces an acceleration of 1.5 m/s^2?
Tuesday, May 14, 2013 at 9:52am

Physics
SD TRUSS PROBLEM WITH THE METHOD OF JOINTS The truss structure ABCD is loaded with a concentrated force P = 2 kN applied at a 45° angle at joint D as indicated in the figure. All bars in the truss have equal cross sectional area and are made of the same homogeneous linear ...
Tuesday, May 14, 2013 at 7:38am

Physics to Elena
Ex=0 ; Ez=0 Ey = 10   sin(3.14x - 6.08e8 t) what is the time-averaged Poynting vector (magnitude and direction) for the position x=y=z=−3 ?
Tuesday, May 14, 2013 at 4:59am

Physics to Elena
An optical fiber is a flexible, transparent fiber devised to transmit light between the two ends of the fiber. Complete transmission of light is achieved through total internal reflection. This problem aims to calculate the minimum index of refraction n of the optical fiber ...
Tuesday, May 14, 2013 at 4:38am

Physics to Elena
At the upper surface of the earth's atmosphere, the time-averaged magnitude of the Poynting vector is referred to as the solar constant and is given by </S/>=1.35×103W⋅mͨ​2;2 . (a) If you assume that the sun's electromagnetic radiation is a ...
Tuesday, May 14, 2013 at 4:38am

physics
A steel rod of length 1m is heated from 25°c to 75°c keeping its length constant.The longitudinal strain developed in the rod is:(steel:12 X 10^-6/°c) "6X10^-4" ; "-6X10^-4" ; "0" please help me as soon as possible by explain this.
Tuesday, May 14, 2013 at 3:07am

Physics
- The Mariana trench is located in the Pacific Ocean at a depth of about 11000 m below the surface of the water. The density of seawater is 1025 kg/m3. (a) If an underwater vehicle were to explore such a depth, what forces would the water exert on the vehicle’s ...
Monday, May 13, 2013 at 11:07pm

physics
Name of physics book for 11 and 12.to catch engineering exam and other competetive exam
Monday, May 13, 2013 at 2:55pm

physics
A resistor of resistance R is connected to a power supply of constant EMF E=12 V and internal resistance r=3 Ω . The energy dissipated in the resistor R is used to heat water. What resistance R in Ohms gives the maximum power dissipated in the resistor?
Monday, May 13, 2013 at 1:30pm

physics
Two point charges +q=1 μC and&​nbsp;−q=−1 μC ​;with mass m=1 g are fixed at the positions ±r⃗ 0&n​bsp;with |r0|=1 m. The charges are released from rest at t=0. ...
Monday, May 13, 2013 at 12:18pm

physics
Three identical conducting spheres are located at the vertices of an equilateral triangle ABC. Initially the charge the charge of the sphere at point A is qA=0and the spheres at B and C carry the same charge qB=qC=q. It is known that the sphere B exerts an ...
Monday, May 13, 2013 at 12:16pm

Physics
Jack and Jill are skating. Jill has a mass of 50 kg, Jack has a mass of 80 kg. At t=0 seconds Jill starts skating across a 50 m diameter rink at a speed of 3 m/s. After 3 seconds Jack skates after her with a speed of 5 m/s. When they meet, Jack scoops up Jill and they glide to...
Monday, May 13, 2013 at 11:35am

physics/chemistry(kinetic ..gasses)
How many degreed of freedom have the gas molecules,if under standard conditions the gas dendity is 1.3kg/m^3 and velocity of sound propagation on it is v=330m/s?
Monday, May 13, 2013 at 10:58am

Physics
At the upper surface of the earth's atmosphere, the time-averaged magnitude of the Poynting vector is referred to as the solar constant and is given by </S/>=1.35×103W⋅mͨ​2;2 . (a) If you assume that the sun's electromagnetic radiation is a ...
Monday, May 13, 2013 at 6:20am

Physics
An optical fiber is a flexible, transparent fiber devised to transmit light between the two ends of the fiber. Complete transmission of light is achieved through total internal reflection. This problem aims to calculate the minimum index of refraction n of the optical fiber ...
Monday, May 13, 2013 at 6:19am

physics
a car weighing 14700N is moving at 20m/s. If the frictional force on it is 2160N , How fast would it be moving when it has travelled 50m
Monday, May 13, 2013 at 6:16am

physics
Adam can run a lap on a certain circular track in 50 seconds. Grampy Sampy can run a lap on this track in 90 seconds. They start at the same location at the same time and move in the same direction. If they each run at a constant speed, how many seconds will it take before ...
Monday, May 13, 2013 at 1:14am

Physics
Susie weighs 100lbs. Sam weighs 150. The seesaw is 20ft long. The seat on one side only is movable in one foot increments. At what distance from the axis should the seat be placed in order for them to balance? Where should each person sit?
Sunday, May 12, 2013 at 11:37pm

physics
Three identical conducting spheres are located at the vertices of an equilateral triangle ABC. Initially the charge the charge of the sphere at point A is q A =0 and the spheres at B and C carry the same charge q A =q B =q. It is known that the sphere B exerts an electrostatic...
Sunday, May 12, 2013 at 10:49pm

Physics-Change in Angular Momentum
What is the change in angular momentum of a planet with radius R if an asteroid mass m and speed v hits the equator at an angle from the west, 40 degrees from the radial direction?
Sunday, May 12, 2013 at 8:36pm

physics
You can paddle at 4.5 km/h and the river is ﬂowing at 3 km/h. How far downstream will you be in 44 min? Answer in units of km
Sunday, May 12, 2013 at 8:12pm

Physics
Calculate the power of a hair dryer that operates on 120V and draws a current of 10 A.
Sunday, May 12, 2013 at 7:59pm

Physics- Simple machines
A wheel and axle arrangement has an axle with a diameter of 25cm. A rope is wrapped around the axle and is supporting a load of 2 tonnes. 1) If the mechanical advantage of the system is 30, determine the diameter of the wheel___________m. 2)Determine the effort required to ...
Sunday, May 12, 2013 at 7:04pm

physics
a man pulls a log of mass 45 kg along level ground by means of a rope at constant speed. If the applied force is at an angle of 30 degrees to the horizontal and the force of friction is 36N find the work done by him pulling the log through a distance of 10m
Sunday, May 12, 2013 at 4:29pm

physics
What is the temperature of 0.54{\rm mol} of gas at a pressure of 1.3{\rm atm} and a volume of 10.9{\rm L} ?
Sunday, May 12, 2013 at 1:40pm

Physics
What is the net upward force on an airplane wing of area 22.0 m2 if the speed of air flow is 315 m/s across the top of the wing and 270 m/s across the bottom?
Sunday, May 12, 2013 at 1:15pm

physics
A small airplane loses a bolt while traveling at a speed of 150 meters/second in the horizontal direction. The bolt follows a parabolic path and lands on the ground after 25 seconds. How far will the bolt have traveled horizontally from the point where it left the plane until ...
Sunday, May 12, 2013 at 12:25pm

Physics
What is the change in angular momentum of a planet with radius R if an asteroid mass m and speed v hits the equator at an angle from the west, 40 degrees from the radial direction?
Sunday, May 12, 2013 at 11:43am

physics
the greatest accerlation or decerlation that a train may have is a.the minimum time in which the train can start from one station from other is > i need it with steps..
Sunday, May 12, 2013 at 11:21am

science physics
a boy is runnig on a striaght road he runs 500 m towards north in 2 m 10 s and then turns back and runs 200m in1 m calculate the average speed
Sunday, May 12, 2013 at 2:08am

physics
A helium balloon has a mass of 0.022 kg, which includes both the helium and the balloon itself. On this balloon, there is 0.290 N of buoyant force pushing the balloon upward. If I let go of the balloon, find the balloon's acceleration rate in the upward direction. If we ...
Sunday, May 12, 2013 at 1:10am

physics
A typical baseball has mass of 150 grams. Suppose a batter hits a fastball pitched to him at 92 mph (which is about 40.89 m/s). After contact, the ball's speed is measured as 104 mph (which is about 46.22 m/s) directly back at the pitcher (who is able to duck out of the ...
Sunday, May 12, 2013 at 1:06am

Physics
A singly charged positive ion has a mass of 5.2x10^-27 kg. After being accelerated from rest through a potential difference of 750V, the ion enters a magnetic field of 0.65T. Calculate the radius of the path of the ion in the field.
Saturday, May 11, 2013 at 11:28pm

Physics
An electron in a television CRT moves toward the front of the tube with a speed of 7.5x10^6 m/s. A magnetic field of 0.04T (on a 50 degrees angle) causes the electrons to accelerate. Determine the acceleration
Saturday, May 11, 2013 at 11:28pm

physics
A small 8.00g metal ball is suspended by a 14.0cm long string in a uniform electric field of 1200 N/C [right] (like in question #20). If the ball has a charge of 3.5x10^-5 C, what angle will the string make in the electric field?
Saturday, May 11, 2013 at 11:27pm

physics(mechanics)
how does the engines get cooled when the vehicle moves in a hill ramp.?i ask this question because its said that cooling fans are drived by the rotation of the engines sothat the cooling fans are mounted in the engine casing.If thats is the case then at ramps engine run slowly...
Saturday, May 11, 2013 at 11:14pm

physics
A plane progressive wave is represented by the wave equation: y=0.1sin⁡(200 ðt-20ðx/17) Where y is in millimetres, t is in seconds, and x is the distance from a fixed origin, O, in metres. Find: The frequency of the wave The wavelength of the wave The speed of ...
Saturday, May 11, 2013 at 10:06pm

Physics
Simple Machines A simple wheel and axle has a wheel diameter of 2.3m and an axle diameter of 92mm. If an effort of 26N is required to raise a mass of 16 kg what is the efficiency of the machine? A- 2.46% B- 95.3% C- 24.1% D- 20.1% E- 65.5% I am having a problem determining ...
Saturday, May 11, 2013 at 3:10pm

Physics
How long does it take to deliver 315 J of energy to 0.850 cm^2 of a wall that it hits perpendicularly?
Saturday, May 11, 2013 at 12:24pm

Physics
We discussed in lectures that traveling Electromagnetic waves in vacuum of the form E⃗ =E0xˆcos(kz−ωt),B⃗​ =B0yˆcos(kz−ωt) satisfy all 4 Maxwell's equations. In lectures, I showed that an application of the generalized ...
Saturday, May 11, 2013 at 11:22am

physics
a 4kg roller is attached to a spring of force constant 100N/m. it slides over a frictionless horizontal road. the roller is displaced from equilibrium position by 10cm and then released. its maximum speed will be?
Saturday, May 11, 2013 at 8:24am

Physics
The cylindrical bar in the figure has a total length L=1.2 m, a diameter d=15 mm, and is confined by fixed supports at the walls A and B. A concentrated axial load FC=30 kN is applied to the bar at point C as indicated in the figure, with LAC>LBC. The bar is homogenous with...
Saturday, May 11, 2013 at 2:46am

Physics
A car that was initially at rest reaches a final speed of +50.0 m/s over a displacement of +55.0 m. What is the magnitude of the acceleration? Find the time it took to travel the first 55 m.
Saturday, May 11, 2013 at 2:17am

physics
problem E2_2 Strain, boundary conditions, displacement and elongation: Part I Plz help.
Saturday, May 11, 2013 at 2:13am

physics
A steel bar of length L=2 m, with modulus E=200 GPa and constant cross sectional area A=200 mm2 is constrained between two walls at its two ends A and B. A distributed axial load, fx(x)=−p0(1−3x2L), with p0=200 kN/m, is applied to the bar only in the 0≤x&#...
Saturday, May 11, 2013 at 12:29am

Physics
Temperature of a diatomic gas is 300k. If the moment of inertia of its molecules is 8.28*10^-38 gm-cm^2. Calculate their root mean square angular velocity.
Friday, May 10, 2013 at 10:15pm

Physics: Manitude of Surface Charge on Dielectric
An empty capacitor has a capacitance of 1.86 μF and is connected to a 12-V battery. A dielectric material (κ = 4.5) is inserted between the plates of this capacitor. What is the magnitude of the surface charge on the dielectric that is adjacent to either plate of the...
Friday, May 10, 2013 at 2:38pm

Physics: Capacitance of Capacitor
Capacitor A and capacitor B both have the same voltage across their plates. However, the energy of capacitor A can melt m kilograms of ice at 0 °C, while the energy of capacitor B can boil away the same amount of water at 100 °C. The capacitance of capacitor A is 8.4...
Friday, May 10, 2013 at 2:37pm

Physics: Potential Difference
Two capacitors are identical, except that one is empty and the other is filled with a dielectric (k = 3.6). The empty capacitor is connected to a 15 -V battery. What must be the potential difference across the plates of the capacitor filled with a dielectric so that it stores ...
Friday, May 10, 2013 at 2:36pm

Physics: Dielectric Constant
A parallel plate capacitor has a capacitance of 9.1 μF when filled with a dielectric. The area of each plate is 2.0 m2 and the separation between the plates is 1.5 x 10-5 m. What is the dielectric constant of the dielectric?
Friday, May 10, 2013 at 2:35pm

Physics
A 50 ohm resistor is connected in series with a 0.2 H inductor, a 40 microFarad capacitor, and an AC Generator yielding 120 v (RMS) at 60 Hz. Find A) the inductive reactance b) the capacitive reactance and c) the total reactance, the impedance Z, and the current in Circuit, I.
Friday, May 10, 2013 at 2:30pm

Physics
A 50 ohm resistor is connected in series with a 0.2H
Friday, May 10, 2013 at 2:27pm

Physics
a transformer with 600 turns in the primary coil is connected to a 120v AC source. If the transformer is to have (3) separate secondary coils that need to give a) 2.5v, b) 6.0v, and c) 450v, then how many turns should each coil have?
Friday, May 10, 2013 at 1:50pm

physics
Two carts with masses of 4.00 kg and 3.24 kg move toward each other on a frictionless track with speeds of 4.90 m/s and 3.35 m/s respectively. The carts stick together after colliding head-on. Find the final speed.
Friday, May 10, 2013 at 8:25am

physics
Caculate the work done when a force of 20N strecthes a spring by 50mm
Friday, May 10, 2013 at 4:32am

Physics
determine the image distance for an object that is 45.0 cm from a double convex lens having a focal length of 15.0 cm
Thursday, May 9, 2013 at 10:46pm

Physics
A block of mass m = 2.80kg is held in equilibrium on a frictionless incline of angle= 56.6 by the horizontal force F. (a) Determine the value of F.(b) Determine the normal force exerted by the incline on the block. Hint: Draw a free-body diagram of the block. Choose a ...
Thursday, May 9, 2013 at 9:37pm

physics
In trying to lift a heavy stone into a moving truck, a worker utilizes rope, a rug, and two long planks of wood. Identify the forces at work in making it too hard for the worker to just lift the stone on his back. HELP!!
Thursday, May 9, 2013 at 5:45pm

Physics
Sphere A, with a charge of +64 C, is positioned at the origin. A second sphere, B, with a charge of -16 C, is placed at +1.00 on the x-axis. Where must a third sphere, C, of charge +12 C, be placed so that there is no net force on it?
Thursday, May 9, 2013 at 4:00pm

physics
Discuss the relationship between motion and force including the following terms: velocity, acceleration, equilibrium, contact force, and field force.
Thursday, May 9, 2013 at 3:56pm

physics
The distance between two planets is 1.6 x 10^6 m. How much time would the light signal take to go from one planet to the other?
Thursday, May 9, 2013 at 12:40pm

Physics
A ball is thrown vertically upward with a speed of 25.0m/s.take acceleration due to gravity 10m/s-2. A how high does it rise B how long does it take to reach its highest point?
Thursday, May 9, 2013 at 12:27pm

physics
if the direction of a magnetic field around a straight wire is counterlcockwise, which direciton is the current traveling?
Thursday, May 9, 2013 at 11:52am

physics
pease answer my phy questions urgenntly
Thursday, May 9, 2013 at 4:08am

physics
Earthquakes are motions of the earth's crust. Essentially, they are big sound waves that travel through the earth. There are two types of waves. The first type is called a longitudinal or P wave, where the earth compresses in the same direction as the wave travels. The ...
Thursday, May 9, 2013 at 2:55am

physics
TWO R WHEN CONNECTED IN PARALLEL GIVE RESULTANT VALUE BECOMES 9 OHM CALCULATE VALUE OF REESISTIVITY
Thursday, May 9, 2013 at 2:50am

physics
TWO METALLIC WIRES AB ARE CONNECTED IN PARALLEL A ASS LENGTH L & RADIUS R V AS LENGHT 2L AND 2R FIND RESISTANCE
Thursday, May 9, 2013 at 2:47am

physics
A PIECE OF WIRE HAVING R are cut into 4 equal parts find R IN 4 EQUAL PARTS WHICH ARE IN PARALLEL
Thursday, May 9, 2013 at 2:37am

physics
a wire has r of 16ohm it is drawn in a wire of half its lenght calculate the r of new wire
Thursday, May 9, 2013 at 2:32am

physics
A uniform 5.9 T magnetic ﬁeld points north. If an electron moves vertically downward (toward the ground) with a speed of 0.85 × 107 m/s through this ﬁeld. The charge on a proton is 1.60×10−19 . a) What is the magnitude of the force acting on it...
Thursday, May 9, 2013 at 1:18am

physics
How does the radiant energy from an incandescent solid differ from the radiant energy emitted by an excited gas?
Wednesday, May 8, 2013 at 11:02pm

Physics
Consider the stability of a ladder of mass m and length L leaning against a wall. A painter wants to be sure the ladder will not slip across the floor. He knows that the frictional force exerted by the floor on the bottom end of the ladder is needed to keep the ladder in ...
Wednesday, May 8, 2013 at 10:43pm

physics
Two parallel narrow slits are at a distance of 0.840 mm apart. Each of them has a width of 0.140 mm. The double slit is illuminated with parallel light of wavelength 546.1 nm. (a) Find the ratio of the intensity of the central maximum to that of its adjacent maximum. (1 : 0....
Wednesday, May 8, 2013 at 10:29pm

Physics
The sled is stuck in the snow. A child pulls on the rope and finds that the sled just barely begins to move when he pulls with a force of 24 N, with the rope at an angle of θ = 33° with respect to the horizontal. The mass of the sled is 14 kg. If the child continues ...
Wednesday, May 8, 2013 at 10:10pm

physics
the gravity on mars is 3.69 meters/second^2. if you had a pendulum on mars that was 1.8 meters long. what would the period be?
Wednesday, May 8, 2013 at 10:02pm

physics
Two parallel narrow slits are at a distance of 0.840 mm apart. Each of them has a width of 0.140 mm. The double slit is illuminated with parallel light of wavelength 546.1 nm. (a) Find the ratio of the intensity of the central maximum to that of its adjacent maximum. (1 : 0....
Wednesday, May 8, 2013 at 9:02pm

Physics sorry for reposting but I really need help
An example of the neutron absorption reaction is . 1 0 n+10 5 B-->7 3 Li+ 4 2 He The rest masses of each particle in atomic mass units (u) are 1 0 n= 1 u 10 5 B=10 u 7 3 Li =7 u 4 2 He= 4 u where 1u=1.66x10^-27 kg. calculate Q Q= in MeV I have the same question please ...
Wednesday, May 8, 2013 at 8:44pm

Physics I need help someone plz help out
An example of the neutron absorption reaction is . 1 0 n+10 5 B-->7 3 Li+ 4 2 He The rest masses of each particle in atomic mass units (u) are 1 0 n= 1 u 10 5 B=10 u 7 3 Li =7 u 4 2 He= 4 u where 1u=1.66x10^-27 kg. calculate Q Q= in MeV I have the same question please ...
Wednesday, May 8, 2013 at 6:51pm

physics
An adult and a child are on a seesaw 14.5 ft long. The adult weighs 152 lb and the child weighs 80 lb. How many feet from the child must the fulcrum be placed so that the seesaw balances?
Wednesday, May 8, 2013 at 5:24pm

Estimate the total binding energy for copper. 550 MeV Estimate the energy, in joules, needed to break a 3.0g copper penny into its constituent nucleons. E= in Joules Please help me out I got 1st part I need the Energy in joules am confused please help me out...thanks Physics...
Wednesday, May 8, 2013 at 5:18pm

Physics
An optical fiber is a flexible, transparent fiber devised to transmit light between the two ends of the fiber. Complete transmission of light is achieved through total internal reflection. This problem aims to calculate the minimum index of refraction n of the optical fiber ...
Wednesday, May 8, 2013 at 4:08pm

Physics
At the upper surface of the earth's atmosphere, the time-averaged magnitude of the Poynting vector is referred to as the solar constant and is given by </S/>=1.35×103W⋅mͨ​2;2 . (a) If you assume that the sun's electromagnetic radiation is a ...
Wednesday, May 8, 2013 at 4:08pm

Physics
Ey=E0sin(kx−ωt), Ez=4E0sin(kx−ωt), the magnetic field can be written in the following way B =[ sin(ωt+(−1)bBkx)(cBxˆ+dB​yˆ+eBzˆ)] In other words: Bx=cBsin(ωt+(−1)bBkx), By=dBsin(ωt+(−1)bBkx), Bz=eBsin...
Wednesday, May 8, 2013 at 4:04pm

Physics
Write down the electric field and associated magnetic field in vacuum for a traveling plane wave with the following properties. The amplitude of the electric vector is E0 and the frequency is ω. The radiation is linearly polarized in the y-z plane at an angle α of &#...
Wednesday, May 8, 2013 at 4:02pm

Physics
A wave solution to Maxwell's Equations is given by E⃗ =E0xˆcos(5.0 z)cos( 1.03e11 t) where z is measured in centimeters and t in seconds. (a) What is the wavelength (in rad/meter) of the wave? (b) What is the index of refraction, n, of the medium? (c) The ...
Wednesday, May 8, 2013 at 3:58pm

An example of the neutron absorption reaction is . 1 0 n+10 5 B-->7 3 Li+ 4 2 He The rest masses of each particle in atomic mass units (u) are 1 0 n= 1 u 10 5 B=10 u 7 3 Li =7 u 4 2 He= 4 u where 1u=1.66x10^-27 kg. calculate Q Q= in MeV I have the same question please ...
Wednesday, May 8, 2013 at 3:53pm

physics
An example of the neutron absorption reaction is . 1 0 n+10 5 B-->7 3 Li+ 4 2 He The rest masses of each particle in atomic mass units (u) are 1 0 n= 1 u 10 5 B=10 u 7 3 Li =7 u 4 2 He= 4 u where 1u=1.66x10^-27 kg. calculate Q Q= in MeV I have the same question please ...
Wednesday, May 8, 2013 at 2:16pm

physics
A20 kg box is suspended from the ceiling by robe that weight of the rope is 1kg find the tension
Wednesday, May 8, 2013 at 1:40pm

Physics to Elena
Estimate the total binding energy for copper. 550 MeV Estimate the energy, in joules, needed to break a 3.0g copper penny into its constituent nucleons. E= in Joules Please help me out I got 1st part I need the Energy in joules am confused please help me out...thanks Physics...
Wednesday, May 8, 2013 at 12:51pm

Physics!
The activity of a sample of 35(upper#) 16(lower#)Sulfer (T 1/2= 7.55x10^6 s) is 2.51x10^5 decays per second. WHat is the mass of the sample? m= in grams PLease help me out...Thank you! :)
Wednesday, May 8, 2013 at 12:46pm

If a galaxy is traveling away from us at 2.0% of the speed of light, roughly how far away is it? t= light years I got 2.4x10^8 light years but its wrong please help me out...thank you
Wednesday, May 8, 2013 at 12:45pm

PHYSICS
A SPRING WITH A CONSTANT K = 8N/m IS STRETCHED 5CM AND RELEASED. IT BOBS UP AND DOWN EVERY 2.5 SECONDS. WHAT IS ITS FREQUENCY, PERIOD, ABD AMPLITUDE
Wednesday, May 8, 2013 at 9:32am

physics
a car is moving with a uniform speed of 72km/h .The driver sees a child at a distance of 50m. he applies brakes to stop the car just before the child. Calculate the acceleration.
Wednesday, May 8, 2013 at 1:54am

Physics Help
Consider a glass with full of water of mass density ρ=1,000 kg/m3 and height h=20 cm. There's a circular hole in the bottom of the glass of radius r. The maximum pressure that pushes the water back into the hole is roughly (on the order of) p=σ/r, where σ=0....
Wednesday, May 8, 2013 at 1:36am

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