Question

A body is released from a height of 20m. If a = 10m/s2 calculate the the velocity of the body when
it is the ground. Also calculate the time it takes to fall through the height.​

Answer 1

Explanation:

s=ut+1/2at2

20=1/2×10×t2

20=5t2

20/5=t2

4=t2.

t=√4=2 seconds.

v=u+at.

v=at

v=10×2

v= 20ms-2.

Note: u, or initial velocity is zero, so it is not considered.

Hope this helped.

Answer 2

Answer: $20m/s^{-2}$

Explanation:

s=ut+1/2at2

20=1/2×10×t2

20=5t2

20/5=t2

4=t2.

t=√4=2 seconds.

v=u+at.

v=at

v=10×2

v= 20ms-2.

Note: u, or initial velocity is zero, so it is not considered.