Two blocks of mass 10kg and 2ktg respectively are connected by an ideal string passing over a fixed smooth pulley as shown in figure. A monkey of 8kg started climbing the string with constant acceleration 2ms^-2 with respect to string at t = 0. Initially the monkey is 2.4m from the pulley. Find the time taken by the monkey to reach the pulley.

Option 1 -

1 sec

Option 2 -

2 sec

Option 3 -

4 sec

Option 4 -

8 sec

4 Views | Posted 3 weeks ago

Asked by Shiksha User

1 Answer

Answered by

alok kumar singh | Contributor-Level 10

3 weeks ago

Correct Option - 2

Detailed Solution:

Let the acceleration of string = a

For 2 kg 20 – T₁ = 2a ………… (i)

For monkey T₂ – 80 – T₁ = 8 (2 – a) …. (ii)

For 10 kg T₂ – 100 = 10a ……. (iii)

$∴ a = 0.8 m / s^{2}$

Acceleration of monkey w.r. to ground

= 2 – 0.8 = 1.2 m/s²

$s = u t + \frac{1}{2} a t^{2}$

$2.4 = 0 + \frac{1}{2} \times 1.2 \times t^{2}$

t = 2 sec

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