A 2.0-kg block slides down a frictionless incline from point A to point B. A force (magnitude P = 3.0 N) acts on the block between A and B, as shown. Points A and B are 2.0 m apart. If the kinetic energy of the block at A is 10 J, what is the kinetic energy of the block at B?
a.
27 J
b.
20 J
c.
24 J
d.
17 J
e.
37 J
[Ques. 2] A block slides on a rough horizontal surface from point A to point B. A force (magnitude P = 2.0 N) acts on the block between A and B, as shown. Points A and B are 1.5 m apart. If the kinetic energies of the block at A and B are 5.0 J and 4.0 J, respectively, how much work is done on the block by the force of friction as the block moves from A to B?
a.
3.3 J
b.
+1.3 J
c.
+3.3 J
d.
1.3 J
e.
+4.6 J
[Ques. 3] A 4.0-kg block is lowered down a 37 incline a distance of 5.0 m from point A to point B. A horizontal force (F = 10 N) is applied to the block between A and B as shown in the figure. The kinetic energy of the block at A is 10 J and at B it is 20 J. How much work is done on the block by the force of friction between A and B?
a.
58 J
b.
53 J
c.
68 J
d.
63 J
e.
47 J
[Ques. 4] A force acting on an object moving along the
x axis is given by
Fx = (14
x 3.0
x2) N where
x is in m. How much work is done by this force as the object moves from
x = 1 m to
x = +2 m?
a.
+12 J
b.
+28 J
c.
+40 J
d.
+42 J
e.
28 J
[Ques. 5] A body moving along the
x axis is acted upon by a force
Fx that varies with
x as shown. How much work is done by this force as the object moves from
x = 1 m to
x = 8 m?
a.
2 J
b.
18 J
c.
10 J
d.
26 J
e.
+18 J
[Ques. 6] An object moving along the
x axis is acted upon by a force
Fx that varies with position as shown. How much work is done by this force as the object moves from
x = 2 m to
x = 8 m?
a.
10 J
b.
+10 J
c.
+30 J
d.
30 J
e.
+40 J
[Ques. 7] A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.5 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force P between A and B?
a.
2.7 J
b.
1.0 J
c.
2.2 J
d.
1.6 J
e.
3.2 J
[Ques. 8] The two masses in the figure are released from rest. After the 3.0-kg mass has fallen 1.5 m, it is moving with a speed of 3.8 m/s. What is the change in mechanical energy done on the system during this time interval by the frictional force on the 2.0 kg mass?
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