Physics Worksheet: Connected Bodies, Pulleys, Lift & Contact Forces
Level: Medium → Higher Difficulty
Questions: 20 Numerical MCQs
Assume: , strings are light and inextensible, and pulleys are smooth unless stated otherwise.
Each question has one correct answer.
Section A — Connected Bodies Through Pulleys
1.
Two blocks of masses 4 kg and 6 kg are connected by a light string passing over a smooth pulley. They are hanging freely on opposite sides. The acceleration of the system is:
A) 1 m/s2
B) 2 m/s2
C) 4 m/s2
D) 6 m/s2
2.
A 5 kg block lies on a smooth horizontal table and is connected over a pulley to a hanging 3 kg block.
The tension in the string is:
A) 12.5 N
B) 15 N
C) 18.75 N
D) 25 N
3.
A 10 kg block on a smooth horizontal table is connected to a hanging 5 kg block. An external horizontal force of 20 N is applied to the 10 kg block away from the pulley.
The acceleration of the system is:
A) 2 m/s2
B) 310 m/s2
C) 4 m/s2
D) 5 m/s2
4.
A 4 kg block on a smooth horizontal table is connected to a hanging 6 kg block. A horizontal force F is applied to the 4 kg block toward the pulley. If the system remains at rest, the value of F is:
A) 20 N
B) 40 N
C) 60 N
D) 80 N
5.
Two blocks of masses 2 kg and 8kg are connected over a pulley. The 2 kg block is on a smooth horizontal table and the 8 kg block hangs vertically.
The tension in the string is:
A) 12 N
B) 16 N
C) 20 N
D) 32 N
Section B — Rope with Limiting Tension
6.
A rope can withstand a maximum tension of 120 N. A person of mass 8 kg climbs upward on the rope with acceleration 5 m/s2.
The tension in the rope is:
A) 80 N
B) 120 N
C) 160 N
D) 200 N
7.
A person of mass 60 kg climbs upward on a rope. The rope can withstand a maximum tension of 720 N.
The maximum upward acceleration of the person without breaking the rope is:
A) 1 m/s2
B) 2 m/s2
C) 10 m/s2
D) 12 m/s2
8.
A person of mass 50 kg climbs downward on a rope with acceleration 2 m/s2. The tension in the rope is:
A) 300 N
B) 400 N
C) 500 N
D) 600 N
9.
A 40 kg person climbs upward on a rope with acceleration 3 m/s2. The rope can withstand a maximum tension of 600 N.
The maximum additional upward acceleration possible before the rope breaks is:
A) 2 m/s2
B) 5 m/s2
C) 7 m/s2
D) 10 m/s2
10.
A person of mass 70 kg is climbing down a rope. The rope can withstand a maximum tension of 560 N.
The minimum downward acceleration required so that the tension does not exceed the limiting value is:
A) 1 m/s2
B) 2 m/s2
C) 4 m/s2
D) 8 m/s2
Section C — Apparent Weight in a Lift
11.
A person of mass 60 kg stands on a weighing machine inside a lift accelerating upward at 2 m/s2.
The reading of the weighing machine is:
A) 480 N
B) 600 N
C) 720 N
D) 800 N
12.
A 50 kg person is standing in a lift accelerating downward at 3 m/s2. The apparent weight of the person is:
A) 250 N
B) 300 N
C) 350 N
D) 500 N
13.
A 70 kg person stands on a weighing machine in a lift. The machine reads 840 N.
The acceleration of the lift is:
A) 2 m/s2 upward
B) 2 m/s2 downward
C) 4 m/s2 upward
D) 4 m/s2 downward
14.
A person of mass 80 kg stands in a lift. The weighing machine reads 640 N. The lift is:
A) Accelerating upward at 2 m/s2
B) Accelerating downward at 2 m/s2
C) Accelerating upward at 4 m/s2
D) Moving downward with constant velocity
15.
A lift is moving upward with an acceleration of 4 m/s2. A 20 kg object is suspended from the ceiling of the lift by a string.
The tension in the string is:
A) 120 N
B) 200 N
C) 280 N
D) 400 N
Section D — Contact Forces Between Bodies
16.
Two blocks of masses 2 kg and 3 kg are placed in contact on a smooth horizontal surface. A horizontal force of 20 N is applied to the 2 kg block.
The contact force between the blocks is:
A) 6 N
B) 8 N
C) 12 N
D) 20 N
17.
Three blocks of masses 2 kg, 3 kg, and 5 kg are placed in contact on a smooth horizontal surface. A force of 40 N is applied to the 2kg block.
The contact force between the 3 kg and 5 kg blocks is:
A) 12 N
B) 20 N
C) 24 N
D) 32 N
18.
Three blocks , , and are in contact on a smooth horizontal surface. A force of 36 N is applied to block C.
The contact force exerted by C on B is:
A) 6 N
B) 12 N
C) 18 N
D) 24 N
19.
Two blocks of masses 5 kg and 10 kg are in contact on a rough horizontal surface. The coefficient of friction between each block and the ground is 0.2. A horizontal force of 60 N is applied to the 5 kg block.
The contact force between the blocks is:
A) 10 N
B) 20 N
C) 30 N
D) 40 N
20.
Three blocks A, B, and C, having masses 2 kg, 4 kg, and 6 kg, respectively, are placed in contact on a smooth horizontal surface. A force 60 N acts on A toward B, while another force 12 N acts on C opposite to the direction of motion.
The contact force between B and C is:
A) 16 N
B) 20 N
C) 24 N
D) 28 N
Answer Key
| Q | Answer | Q | Answer |
|---|---|---|---|
| 1 | B | 11 | C |
| 2 | C | 12 | C |
| 3 | B | 13 | A |
| 4 | C | 14 | B |
| 5 | B | 15 | C |
| 6 | C | 16 | C |
| 7 | B | 17 | C |
| 8 | B | 18 | B |
| 9 | A | 19 | B |
| 10 | B | 20 | B |
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