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 (i) A, (ii) B along the direction of string. What is the tension in the string in each case?

Answer 1

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

When force F is applied on body A:

The equation of motion can be written as:

F – T = m₁a

∴T = F – m₁a

= 600 – 10 × 20 = 400 N … (i)

When force F is applied on body B:

The equation of motion can be written as:

F – T = m₂a

T = F – m₂a

∴T = 600 – 20 × 20 = 200 N … (ii)