Friday

November 28, 2014

November 28, 2014

**Recent Homework Questions About Physics**

Post a New Question | Current Questions

**Physics please help**

Add the two component vectors from Sample Problem 1 algebraically to erify that they equal the given vector The two component vectors are: 8.6m(North) and 12m (west) The given vector is 15m(West 35 degrees North)
*Tuesday, September 30, 2014 at 4:52pm*

**physics**

A soccer ball is kicked at an angle of 30° to the horizontal with an initial velocity of 16 m/s. How far does the soccer ball go? A. 3.8 m B. 6.6 m C. 13.3 m D. 22.6 m i used the formula vf^2-(visin theta)^2 / 2g for this and solved it for 3.3m but none of the answers are...
*Tuesday, September 30, 2014 at 4:16pm*

**Physics**

a boat crosses a .2mi river is heading perpendicularly relative to the shore. its speed in still water is 4mph and the speed of the current is 6mph
*Tuesday, September 30, 2014 at 4:05pm*

**Physics**

I need help setting up this problem. While standing on the roof of a building, a child tosses a tennis ball with an initial speed of 15 m/s at an angle of 20° below the horizontal. The ball lands on the ground 2.8 s later. How tall is the building? Thank you.
*Tuesday, September 30, 2014 at 3:28pm*

**Physics**

I need help setting up this problem. A tennis player serves a tennis ball such that it is moving horizontally when it leaves the racquet. When the ball travels a horizontal distance of 19 m, it has dropped 58 cm from its original height when it left the racquet. What was the ...
*Tuesday, September 30, 2014 at 3:27pm*

**Physics**

HI I'm just looking for an answer for 3 questions as my textbook does not explain the answer. How a tin can loses heat through: 1) Conduction 2) Convection 3) Radiation
*Tuesday, September 30, 2014 at 3:06pm*

**physics**

Suppose a vector V⃗ makes an angle ϕ with respect to the y axis.What could be the x and y components of the vector V⃗ ? Express your answers in terms of the variables V and ϕ separated by a comma.
*Tuesday, September 30, 2014 at 2:48pm*

**physics**

A mass pulled by a constant force accelerates from 10 cm/s to 40 cm/s in 5.5 s. A second force accelerates the same mass from rest to 105 cm/s in 15.0 s. If the first force is known to be 5.0 N, that what is the magnitude of the second force?
*Tuesday, September 30, 2014 at 1:41pm*

**physics**

A block of mass m=8 kg is held at the rest on a smooth (fiction less) 37 degree incline by a horizontal force F. the magnitude of the force F (in N) is:
*Tuesday, September 30, 2014 at 1:23pm*

**Physics**

At a time when mining asteroids has become feasible, astronauts have connected a line between their 3360-kg space tug and a 6300-kg asteroid. Using their ship's engine, they pull on the asteroid with a force of 490 N. Initially the tug and the asteroid are at rest, 430 m ...
*Tuesday, September 30, 2014 at 1:16pm*

**Physics**

A car accelerates from rest at 5 m/s2 for 5 seconds. It moves with a constant velocity for some time, and then decelerates at 5 m/s2 to come to rest. The entire journey takes 25 seconds. On a separate sheet of paper, plot the velocity-time graph of the motion. Describe the ...
*Tuesday, September 30, 2014 at 1:01pm*

**physics**

Find the total force necessary to give a rocket of mass 25,000 slugs an acceleration of 28.0 ft/s2.
*Tuesday, September 30, 2014 at 11:43am*

**physics**

One ball is dropped from a cliff. A second ball is thrown down 1.00 s later with an initial speed of 40.0 ft/s. How long after the second ball is thrown will the second ball overtake the first?
*Tuesday, September 30, 2014 at 10:50am*

**physics**

A woman raises a 65N box 16m in 4 seconds.Calculate the work done by the woman on the box
*Tuesday, September 30, 2014 at 7:38am*

**physics**

This graph in the figure (Figure 1) shows how the temperature of an initially solid sample changes as time goes by when it is placed above a flame that delivers a constant heating power (that is, a fixed amount of energy input in the form of heat each second). The process ...
*Tuesday, September 30, 2014 at 3:34am*

**physics**

A 20kg box rests ona table and a 10kg is placed on top of the 20kg box. Determine the normal force that the table exerts on the 20kg box and the normal force that the 20kg box exerts on the 10kg box. please help
*Tuesday, September 30, 2014 at 3:03am*

**Physics**

Which of the following are the correct units for mass?
*Tuesday, September 30, 2014 at 1:07am*

**Physics**

You want to use a rope to pull a 12-kg box of books up a plane inclined 30∘ above the horizontal. The coefficient of kinetic friction is 0.29. The rope pulls parallel to the incline. What force do you need to exert on the rope if you want to pull the box with a constant ...
*Tuesday, September 30, 2014 at 12:38am*

**physics**

The helicopter in the drawing is moving horizontally to the right at a constant velocity. The weight of the helicopter is W=41600 N. The lift force L generated by the rotating blade makes an angle of 21.0° with respect to the vertical. (a) What is the magnitude of the lift...
*Tuesday, September 30, 2014 at 12:28am*

**Physics**

A certain automobile engine delivers 2.24 ✕ 10^4 W (30.0 hp) to its wheels when moving at a constant speed of 31.0 m/s ( 69 mi/h). What is the resistive force acting on the automobile at that speed?
*Monday, September 29, 2014 at 11:12pm*

**Physics **

A washing machine drum has a diameter of 46 cm and spins at 400 revolutions per minute. Find the centripetal acceleration at the drum's surface. Give your answer in m/s
*Monday, September 29, 2014 at 10:37pm*

**physics 12**

a boeing 747 can travel up to 254m/s. The pilot must travel from vancouver to calgary, which is located 3.0x10^2km [N] and 7.0x10^2km [E]. there is strong wind blowing at 50.0m/s [SE].
*Monday, September 29, 2014 at 10:24pm*

**Physics**

Knowing that at the time of the release the balloon was 73.8 m above the ground, determine the time, τ, it takes the bag to reach the ground from the moment of its release.
*Monday, September 29, 2014 at 9:32pm*

**physics**

A 96.5 kg ice hockey player hits a 0.150 kg puck, giving the puck a velocity of 45.5 m/s. If both are initially at rest and if the ice is friction less, how far does the player recoil in the time it takes the puck to reach the goal 18.0 m away?
*Monday, September 29, 2014 at 9:30pm*

**physics**

A small coin, initially at rest, begins falling. If the clock starts when the coin begins to fall, what is the magnitude of the coin\'s displacement between t1 = 0.1749 s and t2 = 0.437 s?
*Monday, September 29, 2014 at 9:21pm*

**physics**

A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.540 m/s. The total mass of the sled, man, and rock is 93.5 kg. The mass of the rock is 0.300 kg and the man can throw it with a speed of 15.0 m/s. Both speeds are ...
*Monday, September 29, 2014 at 9:11pm*

**physics**

Two ice skaters stand facing each other at rest on a frozen pond. They push off against one another and the 48-kg skater acquires a speed of 0.65 m/s. If the other skater acquires a speed of 0.84 m/s, what is her mass?
*Monday, September 29, 2014 at 8:49pm*

**Physics**

Nellie weighs 300 N and stands on a pair of bathroom scales. If she leans so that one-third of her weight is on the left scale, what is her reading on each scale?
*Monday, September 29, 2014 at 8:21pm*

**physics**

If you stand on a pair of bathroom scales, explain how the readings change as you shift your weight gradually from side to side. what rule governs the readings on the scale?
*Monday, September 29, 2014 at 8:18pm*

**Physics**

a) An electron in an atom has a speed of 2.2 × 10^6 m/s and orbits the nucleus at a distance of 5 × 10^-11m. What is its centripetal acceleration? (already solved) 9.68x 10^22 m/s^2 b) A neutron star of radius 17 km is found to rotate at 5 revolutions per second. ...
*Monday, September 29, 2014 at 8:18pm*

**physics**

A chunk of Martian rock falls off of a cliff and drops 47.7 m in 5.00 s. What is the acceleration due to gravity on the surface of Mars?
*Monday, September 29, 2014 at 7:56pm*

**Physics**

what is the mass density of mercury is 13.6g/cm^3. A cylinder of mercury has a diameter of 1 cm and a height of 76cm. what would the height of the cylinder of the water having a diameter of 1 cm and a mass equal to the mass of the mercury cylinder?
*Monday, September 29, 2014 at 6:10pm*

**physics**

A truck on a straight road starts from rest, accelerating at 2.00 m/s2 until it reaches a speed of 11.0 m/s. Then the truck travels for 65.0 s at constant speed until the brakes are applied, stopping the truck in a uniform manner in an additional 5.00 s. (a) How long is the ...
*Monday, September 29, 2014 at 5:43pm*

**Physics please help**

An ant travels 2.78 cm (West) and then turns and travels 6.25cm (south 40 degrees East). What is the ant's total displacement?
*Monday, September 29, 2014 at 5:41pm*

**physics**

In 10 seconds a car accelerates 3m/s^2 to 90m/s. How fast was the car going before it accelerated?
*Monday, September 29, 2014 at 5:19pm*

**Physics**

A police car is traveling at a velocity of 20.0 m/s due north, when a car zooms by at a constant velocity of 44.0 m/s due north. After a reaction time 0.700 s the policeman begins to pursue the speeder with an acceleration of 6.00 m/s^2. Including the reaction time, how long ...
*Monday, September 29, 2014 at 5:10pm*

**Physics**

rom the top of a cliff, a person uses a slingshot to fire a pebble straight downward, which is the negative direction. The initial speed of the pebble is 7.56 m/s. (a) What is the acceleration (magnitude and direction) of the pebble during the downward motion? (b) After 0.950 ...
*Monday, September 29, 2014 at 4:06pm*

**Physics**

A 103 kg sprinter wishes to accelerate from rest to a speed of 13.2 m/s in a distance of 19.3 m. What coefficient of static friction is required between the runners shoes and the track?
*Monday, September 29, 2014 at 3:53pm*

**Physics**

The electrons that produce the picture in a TV set are accelerated by a very large electric force as they pass through a small region in the neck of the picture tube. This region is 1 cm in length, and the electrons enter with a speed of 1 × 105 m/s and leave with a ...
*Monday, September 29, 2014 at 3:51pm*

**Physics**

A renegade watermelon starts at x = 0 m and rolls at a constant velocity to x = −3.0 m at time t = 5.0 seconds. Then, it bumps into a wall and stops. Draw its position versus time graph from t = 0 s to t = 10 s.
*Monday, September 29, 2014 at 3:13pm*

**physics**

C Exercise 3.57 In laboratory situations, a projectile’s range can be used to determine its speed. To see how this is done, suppose a ball rolls off a horizontal table and lands 1m out from the edge of the table. Part A If the tabletop is 70cm above the floor, determine ...
*Monday, September 29, 2014 at 2:24pm*

**physics**

A certain muon detector counts 600 muouns/h at an altitude of 1900m and 380/h at sea level. Given that the muon half-life at rest is 1.5×(10^-6)s, determine the speed of the muons relative to Earth, assuming they all have the same speed.
*Monday, September 29, 2014 at 11:23am*

**Physics**

Calculate the megnatic force on static electron of megnatic field of 1.4 Tesla????
*Monday, September 29, 2014 at 9:44am*

**Physics**

A lorry of mass 12,000kg traveling at a velocity of 15 m/s crashes into the back of a moving car of mass 1500kg, traveling at a velocity of 5 m/s. The vehicles move together after the impact. Calculate their velocity.
*Monday, September 29, 2014 at 9:16am*

**Physics**

a container weighing a 1.20 x 10^4 N sits on a hydraulic press piston with can area of 0.80m^2. Compressed ir exerts a force of on the second piston which has an area of 0.30m^2 How large must this force be to support the car
*Monday, September 29, 2014 at 5:56am*

**Physics**

joel is running down the newly waxed school corridor and tries to slide across the floor in this rubber shoes. The thick 1.5-cm thick rubber soles each have a cross-sectional area of 0.015m^2 and are sheared with a force of 10,000 N
*Monday, September 29, 2014 at 5:48am*

**Physics**

A 20,000 kg vehicle is running at 80km/hr in a rotonda with a radius of curvature 25m compute for the centripetal force
*Monday, September 29, 2014 at 5:42am*

**Physics**

A train whose speed is 100km/hr rounds a curve whose radius of curvature is 150m what is the acceleration?
*Monday, September 29, 2014 at 5:40am*

**physics**

what is the centripetal force of the train in the previous problem whose speed is 27.8 m/s rounding a curve whose radius of curvature is 150m if the train mass is 8000 kg
*Monday, September 29, 2014 at 5:39am*

**physics**

how to determine the amount of water in the container when you are given a 200g piece of aluminium at 90 degrees celcius is placed in a 100g glass container which holds an unknown amount of water at 20 degrees celcius .if the equilibrium temperature is 21.6 degrees celsius(...
*Monday, September 29, 2014 at 4:34am*

**physics**

how to determine the amount of water in the container when you are given a 200g piece of aluminium at 90 degrees celcius is placed in a 100g glass container which holds an unknown amount of water at 20 degrees celcius .if the equilibrium temperature is 21.6 degrees celsius(...
*Monday, September 29, 2014 at 4:32am*

**physics**

A 50 kg box hangs from a rope. What is the tension in the rope if a. The box is at rest? b. The box has vy = 5.0 m/s and is slowing down at 5.0 m/s2 ?
*Monday, September 29, 2014 at 1:02am*

**physics**

1) The angle of elevation to the bottom of a transmission tower on a hill from an observer standing 1.8 km away from the base of the hill is 5 degrees. The angle of elevation to the top of the tower from the tower is 6.8 degrees. If the distance from the observer to the base ...
*Monday, September 29, 2014 at 1:01am*

**physics**

A 42 kg girl is bouncing on a trampoline. During a certain interval after she leaves the surface of the trampoline, her kinetic energy decreases to 250 J from 520 J. How high does she rise during this interval?
*Monday, September 29, 2014 at 1:00am*

**physics**

A 60.0 kg person, running horizontally with a velocity of 3.80 m/s, jumps onto a 12.0 kg sled that is initially at rest. a) Ignoring the effects of friction during the collision, find the velocity of the sled and person as they move away. b) The sled and person coast 30.0 m on...
*Monday, September 29, 2014 at 12:59am*

**physics**

One object is at rest and another is moving. The two collide in a one-dimensional, completely inelastic collision. In other words, they stick together and move off with shared velocity. The speed of the object that is moving initially is 25 m/s. The masses of the two objects ...
*Monday, September 29, 2014 at 12:58am*

**physics**

A 302 kg motorcycle is accelerating up along a ramp that is inclined 24° above the horizontal. The propulsion force pushing the motorcycle up the ramp is 2860 N, and the air resistance produces a force of 235 N that opposes the motion. Find the magnitude of the motorcycle...
*Monday, September 29, 2014 at 12:56am*

**physics**

Bob, who has a mass of 75 kg, can throw a 500 g rock with a speed of 30 m/s. The distance through which his hand moves as he accelerates the rock forward from rest until he releases it is 1.0 m. a. What constant force must Bob exert on the rock to throw it with this speed? b. ...
*Monday, September 29, 2014 at 12:46am*

**physics**

A car traveling in a straight line has a velocity of 3.19 m/s at some instant. After 5.4 s, its velocity is 12 m/s. What is its average acceleration in this time interval?
*Monday, September 29, 2014 at 12:31am*

**Physics**

A projectile is launched upward at 26m/s at 30 degrees from the horizontal. The whole path of the projectile takes place over level ground. How much time will the projectile be in the air?
*Sunday, September 28, 2014 at 10:52pm*

**Physics**

Which of the following are the correct units for mass? Tons, u, g, slugs, dyn, lb, oz, kg I put g, slugs, and kg but got it wrong. What part do I have wrong?
*Sunday, September 28, 2014 at 10:36pm*

**physics**

A motorcycle has a constant speed of 21.6 m/s as it passes over the top of a hill whose radius of curvature is 100 m. The mass of the motorcycle and driver is 392 kg. Find the magnitude of (a) the centripetal force and (b) the normal force that acts on the cycle.
*Sunday, September 28, 2014 at 10:35pm*

**physics **

A slowly moving train with 15.0- m-long flatcars is passing a station at 11.0 km/h. A person on the station platform tosses rocks onto the moving flatcars at the rate of one every second. If the first rock just hits the front edge of one car, how many rocks will fall onto that...
*Sunday, September 28, 2014 at 9:52pm*

**physics help please**

An airplane has an air speed of 112m/s [N 20 degrees W] and has a ground speed of 106 m/s [N 25 degrees W]. Find the velocity of the wind.
*Sunday, September 28, 2014 at 9:49pm*

**Physics help please **

A student swims at 4m/s. She is swimming from west to east across a river that's is flowing 2.2m/s [S]. A) if the river is 100 m wide, what is the quickest time that she can swim the entire width? B) how far downstream will she be? C) if she decides to go directly across ...
*Sunday, September 28, 2014 at 9:48pm*

**physics**

An electron in the cathode ray tube of a tele- vision set enters a region where it acceler- ates uniformly from a speed of 30100 m/s to a speed of 3.82 × 106 m/s in a distance of 2.97 cm. What is its acceleration? Answer in units of m/s2
*Sunday, September 28, 2014 at 9:33pm*

**physics**

A hunter wishes to cross a river that is 1.0 km wide and that flows with a speed of 4.9 km/h. The hunter uses a small powerboat that moves at a maximum speed of 9.6 km/h with respect to the water. What is the minimum time necessary for crossing?
*Sunday, September 28, 2014 at 9:24pm*

**physics**

An electron, starting from rest and moving with a constant acceleration, travels 5.8 cm in 14 ms. What is the magnitude of this acceleration? Answer in units of km/s2
*Sunday, September 28, 2014 at 9:23pm*

**physics**

You and a friend stand on a snow-covered roof. You both throw snowballs from an elevation of 18 m with the same initial speed of 11 m/s, but in different directions. You through your snowball downward, at 40° below the horizontal; your friend throws her snowball upward, at...
*Sunday, September 28, 2014 at 9:08pm*

**Physics**

A swimmer, capable of swimming at a speed of 1.44 m/s in still water (i.e., the swimmer can swim with a speed of 1.44 m/s relative to the water), starts to swim directly across a 2.21-km-wide river. However, the current is 0.840 m/s, and it carries the swimmer downstream. (a) ...
*Sunday, September 28, 2014 at 8:53pm*

**Physics**

A student swims at 4m/s. She is swimming from west to east across a river that's is flowing 2.2m/s [S]. A) if the river is 100 m wide, what is the quickest time that she can swim the entire width? B) how far downstream will she be? C) if she decides to go directly across ...
*Sunday, September 28, 2014 at 8:52pm*

**Physics**

A tennis ball connected to a string is spun around in a vertical, circular path at a uniform speed. The ball has a mass m = 0.162 kg and moves at v = 4.73 m/s. The circular path has a radius of R = 0.87 m 1)What is the magnitude of the tension in the string when the ball is at...
*Sunday, September 28, 2014 at 8:48pm*

**physics**

A radar antenna is tracking a satellite orbiting the earth. At a certain time, the radar screen shows the satellite to be 118 km away. The radar antenna is pointing upward at an angle of 58.2 ° above the ground. Find (a) the x and (b) the y components (in km) of the ...
*Sunday, September 28, 2014 at 8:47pm*

**physics**

An airplane has an air speed of 112m/s [N 20 degrees W] and has a ground speed of 106 m/s [N 25 degrees W]. Find the velocity of the wind.
*Sunday, September 28, 2014 at 8:41pm*

**Physics**

A force F acts to the right on a 4.81 kg block. A 2.53 kg block is stacked on top of the 4.81 kg block and can slide on it with a coefficient of friction of 0.2 between the blocks. The table has a coefficient of friction of 0.23. The acceleration of gravity is 9.8 m/s 2 . The ...
*Sunday, September 28, 2014 at 8:30pm*

**physics**

A car is moving with a velocity od 10.1m/s [N] while on a ferry that is moving across a lake.if an observer on shore measures the velocity of the car to be 29m/s [N] how quickly is the ferry moving?
*Sunday, September 28, 2014 at 8:25pm*

**physics**

A grasshopper jumps a horizontal distance of 1m from rest, with an initial velocity at a 45 degree angle with respect to the horizontal. Find the initial speed of the grasshopper and the maximum height reached.
*Sunday, September 28, 2014 at 7:38pm*

**Physics HELP**

A ball is thrown horizontally at 15 m/s from a clifftop 60 m above the sea level. Find: a) the time to land; b) the angle at which it hits the water; ° below the horizontal c) the speed at which it hits the water.
*Sunday, September 28, 2014 at 7:24pm*

**physics**

You and your friend are on the roof of a 20 m tall building investigating a free fall. Your friend releases a small rock from rest. You throw another rock simultaneously with your friend aiming it straight down. (a) What initial speed should you supply to the rock so it hits ...
*Sunday, September 28, 2014 at 7:07pm*

**physics**

Car a starts from rest and speeds up with constant accelleration until it reaches its max speed. Car b starts from rest, at the moment car a is at max speed, and speeds up with constant acceleration. How much time elapses between when car b starts moving, and car b passes car ...
*Sunday, September 28, 2014 at 7:02pm*

**Physics**

A ball is thrown at 41° below the horizontal from a rooftop of height 65 m. It lands 2 s later. Find: Find: a) its initial speed b) the point of impact with the ground; m from the base of the building c) the angle at which it hits the ground. ° below the horizontal
*Sunday, September 28, 2014 at 6:25pm*

**Physics**

A freight train has a mass of 1.3 x10^7 kg. if the locomotive can exert a constant pull of 5.4x10^5 N, how long would it take to increase the speed of the train from rest to 71 km/h? Disregard friction. Answer in units of s.
*Sunday, September 28, 2014 at 6:11pm*

**physics**

a tourist being chased by an angry bear is running in a straight line toward his car at a speed of 4.0m/s. the car is d distance away. the bear is 26.0m behind the tourist and running at 6.0m/s. the tourist reaches the car safely. what is the maximum possible value for d.
*Sunday, September 28, 2014 at 5:45pm*

**physics**

A football is kicked off with an initial speed of 65 ft/s at a projection angle of 45 degrees. A receiver on the goal line 63 yd away in the direction of the kick starts running to meet the ball at that instant. What must be his minimum speed (in feet/second) if he is to catch...
*Sunday, September 28, 2014 at 5:44pm*

**physics**

A small relief package is dropped by a helicopter that is descending steadily at 2.0 m/s. a) After 2.5 s, what is the speed of the relief package? b) After 2.5 s, how is the package below the helicopter? I think I need to use the kinematic equations.
*Sunday, September 28, 2014 at 5:41pm*

**Physics **

A system absorbs 1000 Joules of heat and delivers 600 Joules of work, while loosing 100 Joules of heat by conduction to the atmosphere, the change in the internal energy of the system will be. My solution. I used U=Q+A, and my answer was 1600, but its real answer is 300 Joules...
*Sunday, September 28, 2014 at 4:59pm*

**physics**

A robot probe drops a camera off the rim of a 457 m high cliff on Mars, where the free-fall acceleration is 3.7 m/s2. find the time required for the camera to reach the ground. answer in units of s. i dont know if my equation is right: * tfinal= (vinitial + g)(vfinal)
*Sunday, September 28, 2014 at 4:48pm*

**Physics**

Consider two toy cars. Car A starts from rest and speeds up with constant acceleration for a time delta t until it reached a speed of v and then continues to travel at this speed. At the moment car A reaches its maximum speed, car B, starting at rest from the same point that ...
*Sunday, September 28, 2014 at 4:38pm*

**physics**

A rocket blasts off from rest and attains a speed of 59.4 m/s in 14.1 s. An astronaut has a mass of 66.7 kg. What is the astronaut's apparent weight during takeoff?
*Sunday, September 28, 2014 at 4:35pm*

**physics**

A Student drops a rock from a bridge to the water 14.7m below. with what speed does the rock strike the water? the acceleration of gravity is 9.8 m/s^2. andswer in units of m/s.
*Sunday, September 28, 2014 at 4:25pm*

**Physics**

A bullet is fired straight up from a gun with a muzzle velocity of 312 m/s. Neglecting air resistance, what will be its displacement after 1.4 s? The acceleration of gravity is 9.8 m/s 2 .
*Sunday, September 28, 2014 at 4:16pm*

**physics**

A ball is thrown horizontally at 15 m/s from a clifftop 60 m above the sea level. Find: a) the time to land; b) the angle at which it hits the water; ° below the horizontal c) the speed at which it hits the water. m/s
*Sunday, September 28, 2014 at 3:16pm*

**Physics**

A robot probe drops a camera off the rim of a 429 m high cliff on Mars, where the free-fall acceleration is 3.7 m/s2. What equation will be appropriate to find velocity?
*Sunday, September 28, 2014 at 2:59pm*

**Physics**

Consider two toy cars. Car A starts from rest and speeds up with constant acceleration for a time delta t until it reached a speed of v and then continues to travel at this speed. At the moment car A reaches its maximum speed, car B, starting at rest from the same point that ...
*Sunday, September 28, 2014 at 2:40pm*

**Physics**

A meter stick weighs 200 grams and is supported at the center. Three masses of 100, 200, and 150 grams are placed respectively, at the 10-cm, 20-cm and 60 cm points of the meter stick. To balance the meter stick, where must a 300 grams weight be placed on the meter stick?
*Sunday, September 28, 2014 at 2:35pm*

**Physics help please**

A gamma ray with 700KeV energy is Compton-Scattered from an electron. Find the energy of the photon scattered at 110 degrees, the energy of the scattered electron, and the recoil angle of the electron mp=mass of proton=1.673x10^-27 λ=h/mpc(1-cosθ) λ=(6.6261x10^-...
*Sunday, September 28, 2014 at 2:24pm*

**physics**

A bullet is fired straight up from a gun with a muzzle velocity of 214 m/s. Neglecting air resistance, what will be its displacement after 8.2 s? The acceleration of gravity is 9.8 m/s2 . Answer in units of m
*Sunday, September 28, 2014 at 2:19pm*

**Physics**

A plane with a velocity of 111. 9 meters per second at a maximum rate of 6.8 m/s^2 the plane touches the runaway what's the minimum time before it can come to rest? A=6.8m/s^2 V=111.9m/s t=?
*Sunday, September 28, 2014 at 2:18pm*

**Physics**

A tennis ball connected to a string is spun around in a vertical, circular path at a uniform speed. The ball has a mass m = 0.162 kg and moves at v = 4.73 m/s. The circular path has a radius of R = 0.87 m 1)What is the magnitude of the tension in the string when the ball is at...
*Sunday, September 28, 2014 at 1:43pm*

**Physics**

Two rocks are thrown simultaneously from the top of a very tall tower with identical speeds of v = 7.70 m/s, but in two different directions.One of them is thrown with an angle of 10.0 degrees below the horizontal, the other one at an angle of 50.0 degrees above the horizontal...
*Sunday, September 28, 2014 at 1:41pm*

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