A large rock and a small pebble are held at the same height above the ground. (a) Is thegravitational force exerted on the rock greater than, less

A large rock and a small pebble are held at the same height above the ground. (a) Is thegravitational force exerted on the rock greater than, less than, orequal to that exerted on the pebble? Justify your answer. (b) Whenthe rock and the pebble are released, is the downward accelerationof the rock greater than, less than, or equal to that of the pebble?