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Question
Two bodies of masses 10 kg and 20 kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. A horizontal force F = 600 N is applied to
- A,
- B along the direction of string. What is the tension in the string in each case?
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Solution
Horizontal force, F = 600 N
Mass of body A, m1 = 10 kg
Mass of body B, m2 = 20 kg
Total mass of the system, m = m1 + m2 = 30 kg
Using Newton’s second law of motion, the acceleration (a) produced in the system can be calculated as:
F = ma
`:.a = F/m = 600/30 = 20 "m/s"^2`
(i) When force F is applied to body A:
The equation of motion can be written as:
F-T = m1a
T = F - m1a
= 600 – 10 × 20 = 400 N
(ii) When force F is applied to body B:
The equation of motion can be written as:
F – T = m2a
T = F – m2a
∴T = 600 – 20 × 20 = 200 N
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