A force of 300N is used to stretch a horizontal spring with a 0.5kg block attached to it by 0.25m. the block is released from rest and undergoes harmonic motion. Calculate spring constant mechanical energy applied and velocity when x=15cm?​

When you jump from an elevated position you usually bend your knees upon reaching the ground. by doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. in this way the average force your body experiences is a) less than 1/10 as great. b) more than 1/10 as great. c) about 1/10 as great.d) about 10 times as great.