Two identical point charges of +Q are separated by a distance of 10cm I) calculate the work done per unit charge to bring up another charge from far away along a perpendicular bisector of the line joining two charges to the point Midway between the charges.

ii)if one of the charges in part(a)is charged from +Q to -Q, calculate the work done per unit charge to bring up a charge to the same position as above

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?