A point charge of -3. 00 μc is located in the center of a spherical cavity of radius 6. 90 cm inside an insulating spherical charged solid. The charge density in the solid is 7. 35 × 10^−4 c/m^3. Required:
a. Calculate the magnitude of the electric field inside the solid at a distance of 9.40 cm from the center of the cavity.
b. Find the direction of this electric field.

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?