Question

A block of mass 1 kg is connected by a light string passing over two smooth pulleys placed on a smooth horizontal surface as shown. Another block of 1 kg is connected to the other end of the string then acceleration of the system and tension in the string are

• A. 5 ms^-2,5 N
• B. 1 ms^-2,1 N
• C. 1 ms^-2,5N
• D. 5ms^-2, 10N

Answer 1

Answer: (A)

5 ms^-2,5 N

Answer 2

Considering free body diagram,

mg – T = ma (for hanging mass)

and T = ma

(for mass lying on surface)

Adding mg = (m + m)a

or a = mg/2m

∴ a = $\frac { \mathrm { g } } { 2 } = \frac { 10 } { 2 } = 5 \mathrm {~ms} ^ { - 2 }$

and T = 1 × 5 = 5