Question

A stone thrown vertically upwards goes to a height and returns to the ground.Write the expression for the velocity with which it reaches the ground

Answer 1

there is no change in direction of motion of the objects . but due to the earth attractions ,there will be change in magnitude of velocity .Any change in velocity involves acceleration .Whenever an object falls towards the earth ,an acceleration is involved ,this acceleration earth gravitational force of the earth (or acceleration due to gravity )