Question 143: Motion in 1D

Question

A boy standing at the top of a tower of 20 m height drops a stone.  Assuming g = 10 m s$$-$$2, the velocity with which it hits the ground is

Accepted Answer

We know, v
2
= u
2
+ 2gh
Here u = 0
$$ 	herefore $$ v = $$\sqrt {2gh} $$ = $$\sqrt {2 	imes 10 	imes 20} $$ = 20 m/s

Answer

10.0 m/s

Answer

20.0 m/s

Answer

40.0 m/s

Answer

5.0 m/s

Motion in 1D