In the figure shown block B moves down with a velocity 10 m/s. The velocity of A in the position shown is
12.5 m/s
25 m/s
6.25 m/s
None of these
If B moves down at 10m/s . Therefore length of the string between A and the pulley is decreasing at a rate of 20m/s
VAcos37=20m/s VA=20cos37=25m/s