Statement:
A mass of 50 kg is dropped from 20m.
To find out:
The speed of the ball as it hits the ground.
Solution:
- Mass (m) = 50 Kg
- Height (h) = 20 m
- Initial velocity (u) = 0 m/s [The ball was at rest]
- Acceleration due to gravity (g) = 10 m/s^2
- Let the speed of the ball as it hits the ground be v.
- We know the equation of motion for a freely falling body,
- v^2 = u^2 + 2gh
- Putting the values in the above equation, we get
- v^2 = (0)^2 + 2(10)(20)
- or, v^2 = 400
- or, v = √400
- or, v = 20 m/s
Answer:
The speed of the ball as it hits the ground is 20 m/s.
Hope you could understand.
If you have any query, feel free to ask.