Physics 101 Practice Midterm

1) A 10-kg sign is held by two ropes as shown in Figure. What is the tension on rope B?
A) 69 N
B) 72 N
C) 88 N
D) 98 N
Answer: B

2) A 3.00-kg mass and a 5.00-kg mass hang vertically at the ends of a rope that goes over an ideal pulley. If the masses are released, what is the resulting acceleration of the masses?
A) 0 m/s2
B) 3.68 m/s2
C) 2.45 m/s2
D) 6.13 m/s2
Answer: C

3) Refer to Figure. Block A has a mass of 2.60 kg and rests on a smooth table and is connected to block B, which has a mass of 2.40 kg, after passing over an ideal pulley, as shown. Block B is released from rest. What is the acceleration of the masses?
A) 3.92 m/s2
B) 5.10 m/s2
C) 4.71 m/s2
D) 6.54 m/s2
Answer: C

4) Refer to Figure. Block A has a mass of 3.00 kg, block B has a mass of 5.00 kg and block C has a mass of 2.00 kg. The pulleys are ideal and there is no friction between block B and the table. What is the acceleration of the masses?
A) 0.981 m/s2
B) 1.86 m/s2
C) 2.94 m/s2
D) 4.20 m/s2
Answer: A

5) A 40.0-kg crate is being lowered by means of a rope. Its downward acceleration is 2.00 m/s2. What is the force exerted by the rope on the crate?
A) 40.0 N
B) 232 N
C) 312 N
D) 472 N
Answer: C

6) When a mass of 25.0 grams is suspended from a certain spring and lowered slowly until the spring stops stretching, the spring stretches 2.00 cm. What is the spring constant of the spring?
A) 1.25 N/m
A

B) 0.800 N/m
C) 7.85 N/m
D) 12.3 N/m
Answer: D

7) A 3.0-kg and a 5.0-kg box rest side-by-side on a smooth, level floor. A horizontal force of 32 N is applied to the 5.0-kg box pushing it against the 3.0-kg box, and, as a result, both boxes slide along the floor. How large is the contact force between the two boxes?
A) 12 N
B) 20 N
C) 32 N
D) 0 N
Answer: A

8) An object is under the influence of a force as represented by the force vs. position graph as shown in Figure. What is the work done as it moves from 0 to 10 m?
A) 25 J
B) 50 J
C) 100 J
D) 80 J
Answer: C
A roller coaster of mass 80.0 kg is moving with a speed of 20.0 m/s at position A as shown in Figure. The vertical height at position A above ground level is 200 m. Neglect friction and use g = 10.0 m/s2.

9) Refer to Figure above. What is the total energy of the roller coaster at point A?
A) 16.0 × 103 J
B) 20.2 × 103 J
C) 16.0 × 104 J
D) 17.6 × 104 J
Answer: D

10) Refer to roller coaster Figure above. What is the total energy of the roller coaster at point B?
A) 16.4 × 103 J
B) 20.2 × 103 J
C) 17.6 × 104 J
D) 16.4 × 104 J
Answer: C

11) Refer to roller coaster Figure above. What is the speed of the roller coaster at point B?
A) 66.3 m/s
B) 20.0 m/s
C) 46.9 m/s
D) 17.6 m/s
Answer: A

12) Refer to roller coaster Figure above. What is the speed of the roller coaster at point C?
A) 0 m/s
B) 34.6 m/s
Test ID: P101_11_15_12_practice_ mid-02-FALL 2012 Professor A.N. Kocharian
C) 69.2 m/s
D) 20.0 m/s
Answer: B

Two masses M1 = 2.0 kg and M2 = 4.0 kg are attached by a string as shown in the figure. M1 falls vertically down and M2 moves on a frictionless surface. Initially the system is at rest. Use g = 10 m/s2.
13) Refer to Figure. What is the speed of mass M1 just before it touches the ground?
A) 2.3 m/s
B) 2.9 m/s
C) 4.6 m/s
D) 5.8 m/s
Answer: A

A mass is attached to one end of a string. The other end of the string is attached to a rigid support. The mass is released at A and swings in a vertical arc to points B, C, And D, as shown in Figure. Neglect air resistance and use g = 10 m/s2.

14) Refer to Figure. At what point does the mass have the most potential energy?
A) A
B) B
C) C
D) D
Answer: A

15) Refer to Figure above. At what point does the mass have the most kinetic energy?
A) A
B) B
C) C
D) D
Answer: C

16) A 500-kg cannon fires a 4.0-kg projectile with a velocity of 500 m/s relative to the ground. What is the recoil speed of the cannon?
A) 2.0 m/s
B) 4.0 m/s
C) 6.0 m/s
D) 8.0 m/s
Answer: B

17) A 2.00-g bullet traveling at 700 m/s hits and becomes embedded in a stationary 5.00-kg wood block. What is the speed of the block immediately after the bullet has stopped moving relative to the block?
A) 1.0 m/s
B) 4.24 m/s
C) 3.4 m/s
D) 0.280 m/s
Answer: D

18) A 320-g air track cart traveling at 1.25 m/s collides elastically with a stationary 270-g cart. What is the speed of the 320-g cart after the collision?
A) 0.678 m/s
B) 0.106 m/s
C) 1.36 m/s
D) 1.14 m/s
Answer: B