1. QUIZ

2. Imagine a place in the cosmos far from all gravitational and frictional influences. Suppose that you visit that place and throw a rock. The rock will :-
A. Gradually stop. B. Continue in motion in the same direction at constant speed.

3. Imagine a place in the cosmos far from all gravitational and frictional influences. Suppose that you visit that place and throw a rock. The rock will :-
A. Gradually stop. B. Continue in motion in the same direction at constant speed.

4. A 2-kg object is moving horizontally with a speed of 4 m/s
A 2-kg object is moving horizontally with a speed of 4 m/s. How much net force is required to keep the object moving at this speed and in this direction?
Zero Newton. An object in motion will maintain its state of motion. The presence of an unbalanced force changes the velocity of the object.

5. You are being chased through the woods by a moose which you attempted to photograph. The enormous mass of the moose is extremely intimidating. Yet, if you make a zigzag pattern through the woods, you will be able to use the large mass of the moose to your own advantage. Explain this in terms of inertia and Newton's first law of motion.

6. The large mass of the bull moose means that the bull moose has a large inertia. Thus, you can more easily change your own state of motion (make quick changes in direction) while the moose has extreme difficulty changing its state of motion. Physics for better living!

7. A car has mass 900 kg. Calculate the force required for it to accelerate at a rate of 2 m/s2.
1800 N

8. A net force of 15 N is exerted on a book to cause it to accelerate at a rate of 5 m/s2. Determine the mass of the book.
m = 3 kg

9. A 3.5 kg body accelerates from rest to 20 m/s in 5 s. Calculate:
1) its acceleration 2) the force required

10. A 3.5 kg body accelerates from rest to 20 m/s in 5 s. Calculate:
1) its acceleration = 4 m/s2 2) the force required = 14 N

11. A magician pulls a tablecloth out from under dishes and glasses on a table without disturbing them. Which law explains this?
1st law of motion

12. Rockets are launched into space using jet propulsion where exhaust accelerates out from the rocket and the rocket accelerates in an opposite direction. Which law explains this?
3rd law of motion

13. Describe the other force
Baseball pushes glove leftward

14. Describe the other force
Baseball pushes glove leftward
The glove pushes the baseball rightward.

15. Describe the other force
Bowling ball pushes pin leftwards
Pin pushes bowling ball rightward.

16. Describe the other force
Bowling ball pushes pin leftwards

17. Describe the other force
Enclosed air particles push balloon outward

18. Describe the other force
Enclosed air particles push balloon outward
Balloon wall pushes enclosed air particles inwards.

19. While driving down the road, a bug strikes the windshield of a bus
While driving down the road, a bug strikes the windshield of a bus. The bug hits the bus and the bus hits the bug. Which of the two forces is greater: the force on the bug or the force on the bus?
Trick Question! Each force is the same size. For every action, there is an equal ... (equal!). The fact that the firefly splatters only means that with its smaller mass, it is less able to withstand the larger acceleration resulting from the interaction. Besides, fireflies have guts and bug guts have a tendency to be splatterable. Windshields don't have guts. There you have it. ?? ??

20. While driving down the road, a bug strikes the windshield of a bus
While driving down the road, a bug strikes the windshield of a bus. The bug hit the bus and the bus hits the bug. Which of the two forces is greater: the force on the bug or the force on the bus? =
Trick Question! Each force is the same size. For every action, there is an equal ... (equal!). The fact that the firefly splatters only means that with its smaller mass, it is less able to withstand the larger acceleration resulting from the interaction. Besides, fireflies have guts and bug guts have a tendency to be splatterable. Windshields don't have guts. There you have it.

21. Greater than the acceleration of the bullet.
A rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases that expand outward allowing the rifle to push forward on the bullet. The bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is:
Greater than the acceleration of the bullet.
Smaller than the acceleration of the bullet.
The same size as the acceleration of the bullet.
The force on the rifle equals the force on the bullet. Yet, acceleration depends on both force and mass. The bullet has a greater acceleration due to the fact that it has a smaller mass. Remember: acceleration and mass are inversely proportional.

22. Greater than the acceleration of the bullet.
A rifle recoils when fired. This recoil is the result of action-reaction force pairs. A gunpowder explosion creates hot gases that expand outward allowing the rifle to push forward on the bullet. The bullet pushes backwards upon the rifle. The acceleration of the recoiling rifle is:
Greater than the acceleration of the bullet.
Smaller than the acceleration of the bullet.
The same size as the acceleration of the bullet.
The force on the rifle equals the force on the bullet. Yet, acceleration depends on both force and mass. The bullet has a greater acceleration due to the fact that it has a smaller mass. Remember: acceleration and mass are inversely proportional.

23. A = 50 N B = 200 N C = 1100 N D= 20 N E= 300 B F = H G = 50 N