Reference no: EM13338042

A 3 kg box is pushed across a frictionless horizontal floor with a force F = 20 N that makes an angle of 25° with the horizontal. The box moves 18 m.

1) What is the work done by the force F?

529 J
360 J
326 J
210 J
0 J
2) What is the work done by the force of gravity acting on the box?

529 J
360 J
326 J
210 J
0 J
3) What is the work done by the normal force acting on the box?

529 J
360 J
326 J
210 J
0 J
4) If the box starts at rest, what is the final speed of the box?

12.3 m/s
14.7 m/s
16.0 m/s
18.0 m/s
21.9 m/s
A 3 kg box is pushed across a horizontal floor WITH FRICTION by a force F = 20 N that is parallel to the floor. The box moves 18 m. The box moves with CONSTANT SPEED.

5) What is the work done by the force F?

529 J
-529 J
360 J
-360 J
0 J
6) What is the work done by the force of friction acting on the box?

529 J
-529 J
360 J
-360 J
0 J
A skier with a mass of 50 kg starts from the top of a hill (at rest) at height h above ground. The skier glides down the hill to point A where her velocity is vA = 20 m/s and continues up a second hill 8 meters high and back down the other side. Her entire trip up to point C is frictionless. At point C she begins stopping and comes to a complete stop 48 meters later at point D.



7) What is the height h of the first hill?

h = 12.8 m
h = 32.5 m
h = 16.5 m
h = 28.6 m
h = 20.4 m
8) What is the speed of the skier at point B?

0 m/s
12.8 m/s
15.6 m/s
18.3 m/s
20 m/s
9) What is the speed of the skier at point C?

0 m/s
12.8 m/s
15.6 m/s
18.3 m/s
20 m/s
10) When coming down the first hill, at what height off the ground will the SPEED of the skier be half of its value at point A?

at a distance h off the ground
at a distance .75h off the ground
at a distance .5h off the ground
at a distance .25h off the ground
11) What is the magnitude of the work done by friction on the skier in stopping her?

W = 10000 J
W = 11200 J
W = 12300 J
W = 12300 J
W = 12300 J
12) What is the coefficient of friction in the region from C to D?

.425
.587
.615
.736
.822
13) If the mass of the skier were doubled how would the speed at point A change?

increase
remain the same
decrease
14) If the mass of the skier were doubled how would the stopping distance change?

increase
remain the same
decrease
15) If the mass of the skier were doubled how would the magnitude of the work done by friction change?

increase
remain the same
decrease