Ch.5 Quiz Review
1. A 10.5kg crate is pulled 14.3m across a horizontal floor by a force of 95.5N force applied at an angle of 55.0° above horizontal.
Friction provides a constant force of 40.0N opposing the motion.
a) Find the work done by the applied force.
b) Find the work done by friction.
c) Find the work done by gravity (weight).
d) Find the work done by the normal force.
e) If the crate starts at rest, what is its speed after being pulled the 14.3m?
2. A 25,000kg airplane is flying 1000m above the ground at 50m/s.
a) Find the kinetic energy of the airplane.
b) Find the potential energy of the airplane (above ground level).
3 (Skip)
4a. A 99.0kg rock is lifted 30.0m by a crane at a constant speed. What is the work done by the crane?
b. If the crane’s motor has a power of 3.50kW, how long will it take it to lift the rock?
5. A 1.10 x 103kg car travelling at 12.0m/s to the right slows down to a stop in 25.3m. What direction was the net force? What
was the magnitude of the net force on the car? (Hint: Use the work-kinetic energy theorem.)
6. A ball has a kinetic energy of 10.5J. If the ball’s speed is doubled, what is its kinetic energy now?
7. A 350kg roller coaster is going 11.1m/s at the top of a hill in the track that is 25.3m tall. If friction is negligible and can be
ignored, how fast is it going at the bottom of the hill?
Ch.5 Quiz Review
1. A 10.5kg crate is pulled 14.3m across a horizontal floor by a force of 95.5N force applied at an angle of 55.0° above horizontal.
Friction provides a constant force of 40.0N opposing the motion.
a) Find the work done by the applied force.
b) Find the work done by friction.
c) Find the work done by gravity (weight).
d) Find the work done by the normal force.
e) If the crate starts at rest, what is its speed after being pulled the 14.3m?
2. A 25,000kg airplane is flying 1000m above the ground at 50m/s.
a) Find the kinetic energy of the airplane.
b) Find the potential energy of the airplane (above ground level).
3 (Skip)
4a. A 99.0kg rock is lifted 30.0m by a crane at a constant speed. What is the work done by the crane?
b. If the crane’s motor has a power of 3.50kW, how long will it take it to lift the rock?
5. A 1.10 x 103kg car travelling at 12.0m/s to the right slows down to a stop in 25.3m. What direction was the net force? What
was the magnitude of the net force on the car? (Hint: Use the work-kinetic energy theorem.)
6. A ball has a kinetic energy of 10.5J. If the ball’s speed is doubled, what is its kinetic energy now?
7. A 350kg roller coaster is going 11.1m/s at the top of a hill in the track that is 25.3m tall. If friction is negligible and can be
ignored, how fast is it going at the bottom of the hill?
(3a. A 15.0g mass is attached to a spring and is gently lowered until it hangs from the spring. The spring stretches 3.00cm. The
15.0g mass is removed and the same process is repeated with an object of unknown mass and it stretches the same spring 7.00cm.
What is the mass of the object?
b. What is the potential energy stored in the spring when it is stretched 7.00cm?)