Question

A stone is dropped from a tower with 0 initial velocity. It is observed that it strikes the ground after 5 seconds. find the velocity of impact and the height
of the tower

Answer 1

Its initial velocity (u) = 0m/sec
Acceleration due to gravity (g) = 10m/sec^2
So it strikes the ground after 5 seconds.
In 1 second it travels 10m (due to gravity acc.).
So in 5 sec it will travel 5×10= 50m
So height of the tower = 50m
And as velocity increases 10m/sec^2
so in 5 sec its velocity will be 50m/sec.

Hope I m right and it is helpfull for you:-)

Answer 2

v = u + at
= 0 + (9.8 m/s² × 5 s)
= 49 m/s
Velocity of impact of stone is 49 m/s

S = ut + 0.5at²
H = 0 + (0.5 × 9.8 m/s² × (5 s)²)
H = 122.5 m
Height of the tower is 122.5 m