**1. The problem statement, all variables and given/known data**

Find V if the pulley is massless, friction less and

Can take any no of variables but V is be in terms of V

_{P}.Ignore gravity and other forces

**2. The attempt at a solution**

If Pulley comes down by X, the length of string towards left will increase by 2X

Therefore, If in same time pulley comes down by V_{P}, String will increase at rate of V=2V_{P}.

.’. the answer is V=2V_{P}

But the answer is given wrong

The answer in key states V = V_{P}(1+cosβ)

(where β is angle between pulley and increasing string-Left string)

http://ift.tt/1m83M81