phy
posted by mas .
A vertical spring (ignore its mass), whose spring stiffness constant is 1000 N/m, is attached to a table and is compressed down 0.130 m.
(a) What upward speed can it give to a 0.200 kg ball when released?
m/s
(b) How high above its original position (spring compressed) will the ball fly?
m

Energy in compressed spring: 1/2 k .13^2
then, KEreleased=energycompressed spring, from that , find vi
how high? Mgh=1/2 k .13^2 
on a.) it should be 1/2mV^2=1/2kx^2, however whenever I do this problem on my homework I get it wrong. Im not sure why.