QUIZ 2/3

12. A mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the opposite direction has a speed of A) 0 m/s. B) 3 m/s. C) 4 m/s. D) 6 m/s.

A

16. A freely-falling watermelon falls with constant A) velocity. B) speed. C) acceleration. D) distances each successive second.

A

When no forces act on moving objects their paths are normally A) straight lines. B) circles. C) ellipses. D) all of the above

A

1. Inertia is defined as a: A) force. B) property of matter. C) change in motion. D) none

B

14. The average speed of a horse that gallops 10 kilometers in 30 minutes is A) 15 km/h. B) 20 km/h. C) 30 km/h. D) 40 km/h.

B

15. If a car increases its velocity from zero to 60 m/s in 10 seconds, its acceleration is A) 3 m/s2. B) 6 m/s2. C) 60 m/s2. D) 600 m/s2.

B

17. If a freely falling object were equipped with a speedometer, its speed reading would increase each second by about A) 5 m/s. B) 10 m/s. C) 15 m/s. D) a variable amount. E) depends on its initial speed

B

18. Which of the following is not a vector quantity? A) velocity B) speed C) acceleration D) all are vector quantities E) none are vector quantities.

B

A hockey puck sliding across the ice finally comes to rest because A) it seeks its proper and natural state. B) of friction. C) that's just the way it is.

B

10. A sheet of paper can be quickly jerked beneath a container of milk without toppling, which best demonstrates A) net force. B) the difference between force and mass. C) inertia.

C

13. Katelyn runs along the aisle of a train that moves at 8 m/s. Her speed relative to the floor is 3 m/s. Her speed relative to an observer at rest on the ground is A) 5 m/s. B) 11 m/s. C) either depending on her running direction D) none of the above

C

4. The amount of force needed to sustain motion of a rock in outer space is A) a force equal to its weight. B) a force less than its weight if friction is absent. C) none of these

C

7. Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to A) follow a circular path. B) slow down. C) follow a straight-line path. D) stop.

C

11. A mosquito flying at 3 m/s that encounters a breeze blowing at 3 m/s in the same direction has a speed of A) 0 m/s. B) 3 m/s. C) 4 m/s. D) 6 m/s.

D

3. A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is A) equal to its weight. B) equal to its weight divided by its mass. C) equal to its mass times its weight. D) none of the above

D

6. If gravity between the Sun and Earth suddenly vanished, Earth would continue moving in A) a curved path. B) an outward spiral path. C) an inward spiral path. D) a straight-line path.

D

8. Which concept is being illustrated when a tablecloth is quickly yanked beneath dishes resting on a table? A) equilibrium B) friction C) support force D) inertia

D

9. When you flick a card from beneath a coin that hardly moves, you're illustrating A) inertia. B) equilibrium. C) support force. D) friction.

D