Two blocks of mass 10kg and 2kg 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.

Options

A. 1 sec
B. 2 sec
C. 4 sec
D. 8 sec

Answer

B

Explanation

com of both sides will move with same acceleration
`(8(a_(0)-a)-2a)/(10)=(10a)/(10)rArra=(2)/(5)a_(6)`
Acceleration of monkey with respect to ground
`=a_(0)-a=0.6 a_(0)=1.2 ms^(-2)`
`t=sqrt(2(2.4))/(1.2)=2` sec.