Physics Problems Exam Review

Name ______Period ______Physical Science 2nd Semester Review Problems SHOW ALL OF YOUR WORK & DON’T FORGET UNITS!! (5% Extra Credit) (Formulas needed from notes: speed, velocity, acceleration, F=ma, momentum, KE & GPE) 1. A car travels 400.0 miles in a total of 6.0 hours. What is the average speed of the car during the trip?

2. Billy is running late for class. He needs to go down 3 hallways in order to get to class. The first hallway is 45.0 meters long and he travels it in 6.0 seconds; the second hallway is 25.0 meters long and he travels it in 3.0 seconds; and the final hallway is 70.0 meters long and he travels it in 11.0 seconds. What is Billy’s average speed for his trip to class?

3. Vector Problem: A plane heads due North at a speed of 200.0 km/hr. A wind is blowing to the west at 40.0 km/hr that redirects the plane. What is the resultant velocity of the plane? (remember, you need size and direction in your final answer for velocity since it is a vector quantity!!)

4. A family went on a trip. They traveled 140.0 km in 3.0 hours, 250.0 km in 4.0 hours, and then 80.0 km in 2.0 hours. What is the average speed for the family’s trip?

5. A car travels at a velocity of 22.0 m/s. If the car travels for 20.0 minutes, how far will the car travel? (Hint: you will need to convert the time to seconds before using the velocity equation to solve for distance)

6. An object is traveling at 150.0 m/s. How long will it take for the object to travel 2500.0 meters?

1 7. A car traveling at 15.0 m/s starts to decelerate steadily. It comes to a stop in 5.0 seconds. What is the car’s acceleration?

8. A child drops a ball from a bridge (remember, gravity’s acceleration is 9.8 m/s2). The ball strikes the water under the bridge 3.0 seconds later. What is the velocity of the ball when it strikes the water? (Hint: since the ball was dropped, the initial velocity of the ball is zero!!)

9. An automobile with a mass of 1000 kg accelerates when the traffic light turns green. If the net force on the car is 4000 Newtons, what is the car’s acceleration?

10. A car with a mass of 1200 kg accelerates at a rate of 3.0 m/s2. What is the net force acting on the car?

11. A 300.0 N force causes a box to accelerate at 3.0 m/s2. What is the mass of the box?

12. A 2.0 kg ball is traveling at 40.0 m/s. What is the momentum of the ball?

13. What is the mass of a baseball traveling at 150 m/s with a momentum of 0.5 kg?

14. A 1000 kg. car has a momentum 120,000 kg∙m/s. of What is its velocity?

2 15. Conservation of Momentum Problem: Cart A has a mass of 20.0 kg and is traveling at 10.0 m/s to the right. Cart B has a mass of 10.0 kg and is not moving initially. After the collision, Cart A is traveling at 7.5 m/s to the right. After the collision, Cart B is moving to the right as well. a. Draw a sketch below show what is happening before the collision for each cart as well as what is happening after the collision for each cart.

b. Calculate the total momentum of the system before the collision. Make sure that you put appropriate units on your answer. (Cart B does not contribute any momentum to the system because it is not moving before the collision!!)

c. How much momentum does Cart A have after the collision?

d. Knowing the momentum of Cart A after the collision, how much momentum must Cart B have after the collision?

e. How fast must Cart B be moving after the collision?

16. Two cars head towards one another. Car A has a mass of 1000.0 kg and is traveling at 30.0 m/s to the right. Car B has a mass of 1500. 0 kg and is traveling at 35.0 m/s to the left. What is the net momentum of the system?

17. How much work is done in lifting a 8500.0 N piano to a height of 3.5 meters?

18. A 80.0 kg man is walking with a velocity of 2.0 m/s. What is the man’s kinetic energy?

3 19. A 60.0 kg person walks from the ground to the roof of a 75.0 meter tall building. How much gravitational potential energy does this person have at the top of the building?

20. A 40.0 kg tiger has a KE of 15,000 J. How fast is the tiger running?

21. A diver with a mass of 60.0 kg stands motionless at the top of a 4.0 m high diving platform. a. Calculate her GPE while she is standing on the platform.

b. Calculate her velocity as she enters the water.

22. A 0.25 kg ball is thrown into the air and rises to a height of 20.0 meters. How much KE did the ball initially have?

23. What is the kinetic energy of a 2,000 kg boat moving at 5.0 m/s?

24. What is the velocity of a 500 kg elevator that has 4000 J of energy?

25. Determine the amount of potential energy of a 5.0 N book that is moved to three different shelves on a bookcase. The height of each shelf is 1.0 m, 1.5 m, and 2.0 m.

26. You are on in-line skates at the top of a small hill. Your potential energy is equal to 3,000. J. The last time you checked, your mass was 60.0 kg. a. What is your weight in Newtons?

b. What is the height of the hill?

c. If you start rolling down this hill, your potential energy will be converted to kinetic energy. At the bottom of the hill, your kinetic energy will be equal to your potential energy at the top. Calculate your speed at the velocity of the hill.