1. A 19-kg block on a rough horizontal surface is attached to a light spring (force constant = 3.0 kN/m). The block is pulled 6.3 cm to the right from its equilibrium position and released from rest. The frictional force between the block and surface has a magnitude of 38 N. What is the kinetic energy of the block as it passes through its equilibrium position? Select the correct answer.
3.6 J
8.3 J
6.0 J
2.4 J
9.5 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

2. At what rate is the gravitational force on a 3
At what rate is the gravitational force on a 3.7-kg projectile doing work at an instant when the velocity of the projectile is 2.5 m/s directed 33° above the horizontal? Select the correct answer.
- 49 W
+ 49 W
- 91 W
+ 91 W
+ 36 W 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

3. A force acting on an object moving along the x axis is given by Fx = (23x - 5.9x2)N where x is in m. How much work is done by this force as the object moves from x = -1m to x = +5m? Select the correct answer.
+ 28 J
+ 55 J
+ 46 J
+ 42 J
- 55 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

4. A 5. 0-kg body moving along the x axis has a velocity vx = 3
A 5.0-kg body moving along the x axis has a velocity vx = 3.9 m/s at x = 0. The only force acting on the object is given by Fx = (-5.6x)N. where x is in m. For what value of x will this object first come (momentarily) to rest? Select the correct answer.
3.7 m
5.2 m
1.4 m
1.6 m
3.5 m 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

5. A 3. 0-kg particle has an initial velocity of (2i - 5j)m/s
A 3.0-kg particle has an initial velocity of (2i - 5j)m/s. Some time later, its velocity is (6i + 4j) m/s. How much work was done by the resultant force during this time interval, assuming no energy is lost in the process? Select the correct answer.
35 J
62 J
78 J
44 J
21 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

6. A constant force of 10 N in the negative y direction acts on a particle as it moves from the origin to the point (1i + 2j - 7k)m. How much work is done by the given force during this displacement? Select the correct answer.
- 20 J
+ 20 J
+ 73 J
- 73 J
+ 40 J 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

7. If the vectors A and B have magnitudes of 12 and 13, respectively, and the scalar product of these two vectors is -130, what is the magnitude of the sum of these two vectors? Select the correct answer.
7.3
9.6
2.9
7.7
8.3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

8. In a contest, two tractors pull two identical blocks of stone the same distance over identical surfaces. However, block B is moving four times as fast as block A when it crosses the finish line. Which statement is correct? Select the correct answer.
Block B has four times as much kinetic energy as block A.
Block A has lost four times as much kinetic energy to friction as block B.
Block A has lost four times as much kinetic energy as block B.
Both blocks have had equal losses of energy to friction.
No energy is lost to friction because the ground has no displacement. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

9. A 3.8-kg block sliding on a frictionless horizontal surface is attached to one end of a horizontal spring (k = 820 N/m) which has its other end fixed. The speed of the block when the spring is extended 23 cm is equal to 5.3 m/s. What is the maximum speed of this block as it oscillates? Select the correct answer.
6.3 m/s
4.1 m/s
3.4 m/s
8.7 m/s
5.7 m/s 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50