Unit IV problem solving worksheet
Solve the problems below. Each question is worth 10 points. You must show your work with as much detail as possible. Answer the questions directly in this template. Before doing so, it is highly recommended that you thoroughly review the Unit IV Lesson in the study guide.
1. A boy exerts an average force of 100 N on a shopping cart for 0.5 seconds. What is the impulse?
2. In an effort to participate in a science fair, Alice designed a toy car engine that can generate a total impulse of 100 Ns. The mass of the toy car is 2 kg. What is the final speed that her toy car attains when moved from rest? Ignore frictional forces.
3. Curious George observed an interesting event in an international toy exhibition. Two toy cars were moving forward in a monorail. Toy car #1, weighing 10 kg, was ahead of toy car #2, weighing 20 kg, in the beginning, but they collided and joined together. The initial velocity of toy car #1 is 10 m/s and that of toy car #2 is 20 m/s. What is the final velocity of both of these cars after they are connected? Assume that there is no friction in this system.
4. In an isolated system, a 2kg ball with an initial velocity of 3 m/s hits a 5 kg ball that is initially at rest. What is the total kinetic energy before the collision? If the total kinetic energy after the collision is the same as that before the collision, is this an elastic collision or inelastic collision?
5. Consider an inelastic collision between a green ball and an orange ball. The mass m of the green ball is 1 kg and the mass M of the orange ball is 3 kg. Before the collision, the orange ball was at rest and the initial velocity of the green ball was 5 m/s. After the collision, they were combined as one object as shown in the following. What is the final velocity V?
6. A wheel spins counterclockwise through three revolutions for 2 seconds. What is the average angular velocity of the wheel?
7. The fan blades of a jet engine in an airplane rotate counterclockwise with an initial angular velocity of 100 rad/s. As the airplane takes off, the angular velocity of the blades reaches 400 rad/s in 10 seconds. Calculate the average angular acceleration.
8. A new car takes 10 seconds to accelerate from rest to 30 m/s. Its mass is 1500 kg. What is the net average force that acts on the car?
9. A 2 kg ball, moving to the right at a velocity of 2 m/s on a frictionless table, has an elastic head-on collision with a stationary 5 kg ball. What is the total kinetic energy before the collision? What is the total kinetic energy after the collision?
10. Starting from rest, Amy and Jane push off against each other on the smooth frictionless ice rink. The mass of Amy is 50 kg and that of Jane is 60 kg. Amy moves to the right (positive direction) with a velocity of 3 m/s. What is the recoil velocity of Jane?
