Question

A boy wishes to make
a catapults out of
a rubber band of width 9mm and thickness 1.55mm. Determine the length of the band
he must use so that when the stretches it by 0.25
of its natural length and releases it, the velocity of the pebble of mass 0.0006kg is
30ms - Take the youngs modulus of the rubber
to be 4x10000000nm-2
​

Answer 1

I thinking is 2400000