In the arrangement as shown in the figure below, the ends P and Q of an inextensible string move downwards with uniform speed u. Pulleys A and B are fixed. Mass M moves upward with a speed:
None, I am not sure whether it falls under general physics or homework section. [/B]
The Attempt at a Solution
The strings move with velocity u in their respective directions , thus block will move with velocity 2ucosθ. Since each of the two strings has velocity in vertical direction as ucosθ .
But the answer says it is u/cosθ . Which seems right as when you take components of this total velocity of block M in directions of strings, it gives components as u, but those 2 components don't add up to 2ucosθ. What is the mistake here ? Why are they not adding up to ucosθ?
Thank you for all the support and help.