A compressor does 92 joules of work to compress air conditioner refrigerant. The refrigerant later expands and goes back to equilibrium. According to the First law of thermodynamics, how much thermal energy does the refrigerant release when it expands? a) 2.4 joules
b) 38 joules
c) 92 joules
d) 221 joules

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?