Hot water at 50°c is routed from one building in which it is generated to an adjoining building in which it is used for space heating. transfer between the buildings occurs in a steel pipe ( 60 w/m·k) of 100-mm outside diameter and 8-mm wall thickness. during the winter, representative environmental conditions involve air at [infinity] -5°c and 1.5 m/s in cross flow over the pipe.

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?