If the blocks A and B are moving towards each other with accelerations a and b shown in fig. find the net acceleration of block C.

Options

A. `ahat(i)-2(a+b)hat(j)`
B. `-(a+b)hat(j)`
C. `ahat(i)-(a+b)hat(j)`
D. None of these

Answer

A

Explanation

From length constraint `l_(1)+l_(2)+l_(3)+l_(4)=C`
`l_(1)^('')+l_(2)^('')+l_(3)^('')+l_(4)^('')=0`
`(-a-b)+0+(-a-b)+c=0`
`c=2a+ab`
From wedge cosntraints, acceleration of C is right side is a.
Acceleration of C w.r.t ground =`a hat(i)-2(a+b)hat(j)`.