A bullet of a mass of 20 grams leaves the barrel of a rifle with a velocity of 700m/s. The length of the barrel is 60 cm.
a. What is the average acceleration of the bullet as it travels the length of the barrel.
b. Find the average force on the bullet as it travels inside the barrel.
c. Suppose the rifle is 1m above the surface of a smooth (and level) body of water. Ignoring air friction, and assuming barrel of the rifle is exactly horizontal, how much time elapses until the bullet strikes the water?
Suppose an 80 kg skier is sliding down a hill which makes an angle of 10 degrees with the horizontal. The coefficient of kinetic friction between the snow and skis is 0.08.
a. Draw a free-body diagram of the skier, labeling all forces.
b. Determine the normal force and the force of friction.
c. Determine the component of the weight which is parallel to the incline.
d. Find the net force on the skier and determine his acceleration. Is he speeding up or slowing down?
This solution provides the answers to several physics questions.