# physics

The speed of a moving bullet can be determined by allowing the bullet to pass through
two rotating paper disks mounted a distance d apart on the same axle (Fig. below). From the angular
displacement of the two bullet holes in the disks and the rotational speed of the disks, we can
determine the speed v of the bullet. Find the bullet speed for the following data:
d = 80 cm, = 900 rev/min, and angular displacement = 31.0

1. 👍
2. 👎
3. 👁
4. ℹ️
5. 🚩
n = 900 rev/min =900/60 =15 rev/s
t=φ/ω= φ/2πn=0.54/2π•15=0.006 s
v=d/t =0.8/0.006 = 133 m/s

1. 👍
2. 👎
3. ℹ️
4. 🚩

## Similar Questions

1. ### Phyiscs

A 5.00g lead bullet is fired into a wooden fence post. The initial speed of the bullet is 250m/s, and when it comes to rest, half its kinetic energy goes into heating bullet. How much does the bullet's temperature increase?

2. ### Physics

A 35.0-g bullet moving at 475 m/s strikes a 2.5-kg wooden block. The bullet passes through the block, leaving at 275 m/s. The block was at rest when it was hit. How fast is it moving when the bullet leaves?

3. ### Physics

A 2.50g bullet, traveling at a speed of 425m/s, strikes the wooden block of a ballistic pendulum. The block has a mass of 270g (a) find the speed of the bullet/block combination immediately after the collision (b) how high does

4. ### physics

a 15-g bullet is fired from a rifle. it takes 2.50 * 10^-3s for the bullet to travel the length of the barrel, and it exits the barrel with a speed of 715 m/s. assuming that the acceleration of the bullet is constant, find the

1. ### Physics

1. A bullet of 0.0500 kg is fired into a block of wood. Knowing that the bullet left the gun with a muzzle velocity of 350. m/s, and the bullet penetrates .15 m into the block of wood, determine: a) The average force required to

2. ### physics

as shown in the figure a bullet of mass 0.010 kg moving horizontally suddenly strikes a block of wood of mass 1.5 kg that is suspended as a pendulum. The bullet lodges in the wood, and together they swing upward a vertical

3. ### Physic

A 20g bullet moving at 200ms hit a bag of sand and comes to rest in 0.011 s what is the momentum of the bullet just before hitting the bag? find the average force that stopped the bullet

4. ### physics

A heavy wooden block rests on a flat table and a high-speed bullet is fired horizontally into the block, the bullet stopping in it. How far will the block slide before coming to a stop? The mass of the bullet is 10.5 g, the mass

1. ### physics

In a police ballistics test, a 10.0-g bullet moving at 300 m/s is fired into a 1.00-kg block at rest. The bullet goes through the block almost instantaneously and emerges with 50.0% of its original speed. What is the speed of the

2. ### physics

A 10-g bullet of unknown speed is shot horizontally into a 2-kg block of wood suspended from the ceiling by a cord. The bullet hits the block and becomes lodged in it. After the collision, the block and the bullet swing to a

3. ### Physics

A 0.03-kg bullet is fired vertically at 200m/s into a 0.15-kg baseball that is initially at rest. The bullet lodges in the baseball and, after the collision, the baseball/bullet rise to a height of 37m. (a). What was the speed of

4. ### physics

In an experiment to measure the speed of a bullet, the bullet is red into a piece of plasticine suspended from a rigid support by a light thread. (there is a pendulum and two balls, ball one is completely vertical and the bullet