View Full Version : Velocity and energy
Muruga210
Jan 24, 2014, 07:55 AM
A man 50kg runs at a speed of 9m/s, stops for 0.3s, then makes a high jump to a height of 1.5m. What is his acceleration at the start of the jump?
ebaines
Jan 24, 2014, 08:47 AM
Show us yor attempt at solving this and we'll give you some guidance if needed. But given the fact that the man stopped before jumping - what do you think that means with respect to the any effect on his acceleration when he makes the jump?
Muruga210
Jan 24, 2014, 10:26 AM
I calculated the velocity at the start of the jump by equating the P.E and K.E and got 4.95m/s. He pushes his feet for 0.3s before taking the jump. The question asks for his acceleration.
Thanks for trying to help me!
ebaines
Jan 24, 2014, 12:48 PM
If you assume that his acceleration is constant during that 0.3 seconds, then you can use
a = delta v/time