Unit IV problem solving worksheet
This assignment will allow you to demonstrate the following objectives:
4. Apply the concept of momentum conservations to daily life.
4.1 Relate impulse-momentum theorem to Newton’s second law.
4.2 Show the relationship between linear momentum conservation and Newton’s third law.
4.3 Apply momentum conservation to rotational kinematics.
5.Identify the total mechanical energy conservation.
5.1 Interpret total kinetic energy conservation in elastic collision.
A boy exerts an average force of 100 N on a shopping cart for 0.5 seconds. What is the impulse? Hint: See Sample Question 1 in the Unit IV Lesson.
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. Hint: See Sample Question 2 in the Unit IV Lesson.
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. Hint: See Sample Question 3 in the Unit IV Lesson and Example 5 on page 181 to 182 in the textbook.
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? Hint: See Sample Question 4 in the Unit IV Lesson and Example 7 on page 185 in the textbook.
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? Hint: Use the momentum conservation law.
A wheel spins counterclockwise through three revolutions for 2 seconds. What is the average angular velocity of the wheel? Hint: See Example 3 on page 204 in the textbook.
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. Hint: See Example 4 on page 205 in the textbook.
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? Hint: Use the equation (7.3) on page 176 in the textbook.
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?
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? Hint: See Example 6 on page 182 in the textbook.