14. a block rests on a frictionless table on earth. after a 20-n horizontal force is applied to the block, it accelerates at 3.9 m/s2. then the block and table are carried to the moon, where the acceleration due to gravity is 1.62 m/s2. a horizontal force of 10 n is then applied to the block. what is the acceleration?

a. 1.8 m/s2
b. 2.5 m/s2
c. 2.1 m/s2
d. 2.3 m/s2
e. 2.0 m/s2

15. workers are trying to free an suv stuck in the mud. to move the vehicle, they use three ropes held parallel to the ground, producing the force vectors shown in the figure. what is the magnitude and direction of the resultant force of the three pulls?

a. 2160 n at 35.5° counterclockwise to the x-axis
b. 16 50 n at 65.9° counterclockwise to the x-axis
c. 866 n at 78.1° counterclockwise to the x-axis
d. 1510 n at 83.2° counterclockwise to the x-axis

16. a large sphere has a mass of 175 kg and is suspended by a chain from the ceiling. the mass of the chain is 12.0 kg. what is the tension in the chain?

a. 1940 n
b. 1830 n
c. 1610 n
d. 1720 n

17. two chains are available to hold up an object. a student arranges the object and either one or two chains according to the diagrams shown here. which arrangement generates the most tension in one chain?

a. b
b. d
c. a
d. c

18. a force of gravity between the sun and its planets holds the planets in orbit around the sun. if that force of gravity suddenly disappeared, in what kind of path would the planets move?

19.
a car of mass 1200 kg is traveling at 2 m/s. then it collides with a heavy boulder in the road. during the collision, the car moves forward only 15 cm before stopping. what is the average force exerted by the boulder on the car?

a. 1.8 × 104 n
b. 1.6 × 104 n
c. 5.4 × 104 n
d. 3.2 × 104 n
e. 6.5 × 105 n

20. which type of force can act through empty space?

a. magnetism
b. normal
c. spring
d. tension

21. a 5.0-kg block and a 4.0-kg block are connected vertically by a 0.6-kg rod. in the diagram, the links between the blocks and the rod are denoted by the letters a and b. a force -> f is applied to lift the upper block. the blocks and rod assembly move upward at constant velocity.
what is the magnitude of the force in link a?

a. 41 n
b. 39 n
c. 47 n
d. 43 n
e. 45 n

22. at which location would a bowling ball have the greatest weight?

a. on earth, several kilometers below the surface
b. on the surface of the moon
c. on earth at sea level
d. on earth, at the top of a tall mountain

23. a worker with spikes on his shoes applies a constant horizontal force of 20 n to push a 40-kg box across a frictionless, frozen lake. what is the acceleration of the box?

a. 0.5 m/s2
b. 2.0 m/s2
c. 8.0 m/s2
d. 4.1 m/s2

24. a batter swings a bat and hits a baseball into the outfield. during the collision between bat and ball, how do the forces on the two objects compare?

a. the forces are opposite in direction, with the force on the ball much stronger in magnitude.
b. the forces are opposite in direction, with the force on the bat much stronger in magnitude.
c. both forces are equal in magnitude and direction.
d. both forces are equal in magnitude but opposite in direction.

25. a superhero throws a 2400-n boulder at an adversary. what horizontal force must the superhero apply to the boulder to provide it with a horizontal accelertion of 12.0 m/s2?

a. 245 n
b. 2940 n
c. 28800 n
d. 200 n

26. the acceleration due to gravity on the surface of mercury is 3.71 m/s2. an object with a mass of 8.69 kg has what weight on mercury?

a. 23.4 n
b. 85.2 n
c. 42.7 n
d. 32.2 n