The force required to stretch a Hooke’s-law spring varies from 0 N to 75.2 N as we stretch
the spring by moving one end 13.6 cm from
its unstressed position.
1.) Find the force constant of the spring.
Answer in units of N/m.
2.) Find the work done in stretching the spring.
Answer in units of J.

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?