Five objects of different masses are simultaneously released vertically downwards from height 'h' (in air).…
Five objects of different masses are simultaneously released vertically downwards from height 'h' (in air). Which physical quantity associated with the objects will
change at the instant they strike the ground ? (Neglect the air resistance.)
Momentum
Time
Acceleration
Velocity
Solution
When five objects of different masses are released from the same height $h$, neglecting air resistance:
- Time of fall: All objects take the same time to hit the ground since the acceleration due to gravity is the same for all objects.
- Acceleration: It remains constant $(g)$ for all objects.
- Velocity upon impact: The final velocity $(v=\sqrt{2 g h})$ is the same for all objects, regardless of their masses.
- Momentum: Momentum depends on both mass and velocity ( $p=m v$ ). Since the masses are different, their momenta will differ when they strike the ground.