Barrack Obama fires a 8 g bullet out of a 5 kg rifle at a speed of 95 m/s. (a) What is the recoil speed of the rifle? (b) When the bullet hits the target, it takes 0.35 s to stop. (c) What force does the bullet apply on the target?

A bow is drawn so that it has 50 J of potential energy. When fired, the arrow will ideally have a kinetic energy that is

Suppose you made a hole all the way through the middle of the Earth. (a) If you fell in the hole, would the force of gravity increase or decrease? (b) If your acceleration due to gravity is 10 m/s2 when you enter the hole, what is the acceleration at the center of the Earth (include direction)? (c) What is the acceleration due to gravity when you exit the other side (include direction)?

A butter gun fires butter out of a gun to a piece of bread which covers one piece of bread at a distance of 1 foot. (a) How many pieces of bread will the butter gun cover if the target is moved back to 2 feet? (b) How thick is the butter compared to the first piece of bread? (c) How many pieces of bread will the butter gun cover if the target is moved back to 3 feet? (d) How thick is the butter compared to the first piece of bread?

Q2 In a control system, the actuating signal is:

Below is a picture of a vibrating string. (a) What kind of wave is this? (b) The instructor sets the frequency to 25 Hz in the first picture. He then changes to a new frequency. How many nodes are there in the first picture? (c) How many antinodes? (d) How many nodes are in the second picture? (e) How many antinodes? (f) What is the frequency associated with the second picture? before.jpgafter.jpg

The fact that desert sand is very hot in the day and very cold at night is evidence that sand has

A floating leaf oscillates up and down two complete cycles in one second as a water wave passes by. The wave’s wavelength is 10 meters. What is the wave’s speed?

Inhaling helium increases the pitch of your voice. One reason for this is that sound travels

An ambulance is coming toward your car. (a) What happens to the frequency of the sound as the ambulance approaches you? (b) What happens to the frequency of the sound as the ambulance passes you? (c) What is the name of this phenomenon? (d) Can this also occur with light?