Consider a stone at rest on the ground. there are two interactions that involve the stone. one is between the stone and the earth; earth pulls down on the stone and the stone pulls up on the earth. what is the other interaction? 1. all are wrong. 2. between the ground and the earth 3. between the ground and air 4. between the earth and air 5. between the stone and the ground

5. between the stone and the ground

for a stone at rest on the ground, we have two forces acting on the stone. first is the force on the stone by the earth due to gravity of earth. second is the force applied by the ground in upward direction to balance the force of gravity on the stone.

so first interaction is between earth and stone : earth pulls stone towards it and stone pulls earth towards it by same amount of force.

second interaction is between stone and ground : ground push the stone in upward direction and stone push the ground in down direction by same amount of force.

hence the correct choice is

5. between the stone and the ground

the maxium height is 34m/s