1. Unit 1 Quiz #2 Forces & Interactions
Read each question and all answers carefully. Eliminate obvious wrong answers, then choose the best remaining answer.
Do not waste time as you will have one minute to answer each question.
No going back!

2. 26. What is Newton’s third law of motion? Inertia
MS-PS2-1
26. What is Newton’s third law of motion?
Inertia
The relationship between mass and acceleration.
Action and reaction forces.
Overcoming friction.

3. 27. Objects in motion will ___________ until acted upon by another force.
remain in motion
lose potential energy
lose kinetic energy
lose both potential and kinetic energy

4. 28. Why do rockets move up toward space?
Thrust is equal to gravity.
Thrust is less than gravity.
Thrust is greater than gravity.
Gravity is greater than thrust.

5. 29. Two gliders with the initial velocities and masses shown below hit each other in a perfectly elastic collision (elasticity 1.0). What will the velocity of glider 2 be after the collision?
0 m/s.
2 m/s.
4 m/s.
6 m/s.

6. 30. Glider 1 starts with a mass of 2. 4 kg and a velocity of 3. 0 m/s
30. Glider 1 starts with a mass of 2.4 kg and a velocity of 3.0 m/s. What is Glider 1's starting momentum?
2.4 kg•m/s
5.4 kg•m/s
7.2 kg•m/s
10.8 kg•m/s

7. 31. Given the starting conditions shown below and a perfectly elastic collision, what will be the total momentum of both gliders after they collide?
-7.0 kg•m/s
-9.0 kg•m/s
-13.0 kg•m/s
-21.0 kg•m/s

8. 32. Inertia is described by Newton’s ______.
MS-PS2-2
32. Inertia is described by Newton’s ______.
first law of motion
second law of motion
third law of motion
law of gravitation

9. 33. With a constant force, what will make acceleration decrease?
Decrease the weight.
Increase the weight.
Increase the mass.
Decrease the mass.

10. 34. How could you increase the number of snowmen destroyed by the sled sliding down the hill?
Increase the starting height of the sled.
Increase the mass of the sled.
Increase the starting kinetic energy of the sled.
All of the above.

11. 35. What might cause a car parked on a hill to start to roll backwards?
An unbalanced force.
A frictional force.
A balanced force.
An inertial force.

12. 36. Find the net force on the object shown.

13. 37. Find the net force on the object shown.

14. 38. According to Newton’s second law of motion, what is the relationship between mass and acceleration?
Inversely proportional to each other.
If mass increases, acceleration increases
Mass equals acceleration
Proportional to each other.

15. 39. What changes when an unbalanced force acts on a moving object?
Speed
Direction
Neither speed nor direction
Either speed or direction

16. 40. Action forces and reaction forces are described by which of Newton’s Laws?
First law of motion.
Second law of motion.
Third law of motion.
The law of universal gravitation.

17. 41. Balanced forces are always opposite in _______.
direction
size
size and direction
size or direction

18. 42. Based on the setup above, which of the following statements is true?
The car will easily smash the egg.
The car will just barely crack the egg.
The car will touch the egg but won't break it.
The car will never reach the egg.

19. 43. Assuming there is no friction, which of the following is the reason for the correct answer to question #19 above?
Potential energy converts to kinetic energy as the car moves forward allowing the car to reach and smash the egg.
The car has just enough potential energy to get the car to the egg.
The car starts at a lower height that the egg, so there is not enough gravitational potential energy to reach the egg.
The car will transfer its kinetic energy to the egg and the egg will roll away.

20. 44. Which of the following statements about the energy of a pendulum is true?
The kinetic energy is always greater than both the potential energy and the total energy.
The total energy is always greater than both the potential energy and the kinetic energy.
The potential energy is always greater than both the kinetic energy and the total energy.
All of the above may be true.
None of the above are true.

21. None of these are correct.
MS-PS3-5
45. Which of the following statements are true about energy and energy transfer?
Energy is neither created nor destroyed, only transformed from one type to another.
If you drop a ball, the ball will bounce to the same height that it was dropped from.
Potential energy converts to kinetic energy as a roller coaster starts downhill, then back to potential energy as it goes back up.
Both A and C are correct.
None of these are correct.

22. 46. The two sleds shown below are about to collide
46. The two sleds shown below are about to collide. If they stick together in the collision, what will happen after the collision? (In this collision, there is no friction between the sleds and the snow.)
The two sleds will move to the left.
The two sleds will move to the right.
The two sleds will be motionless in the middle.
The sleds will move back and forth and never stop.