Question

A body is dropped from a height of 320m. The acceleration due to the gravity is 10m/s2? (a)How long does it take to reach the ground? (b) What is the velocity with which it will strike the ground?

Answer 1

Given:-

Height(h)=320m

Acceleration due to gravity(g)=10m/s²

Initial velocity(u)=0

To find:-

a.Time taken by body to reach the ground(t)

b.Final velocity of the body(v)

Solution:-

Since u=0,thus by using h=1/2gt²,we get----

=>320=1/2×10×(t)²

=>320=5t²

=>t²=320/5

=>t²=64

=>t=8s

By,using v=u+gt,we get-----

=>v=0+10×8

=>v=80m/s

Thus,time taken is 8s and final velocity is 80m/s.

Answer 2

Answer:

v= 80 is the right answer

hope it's help you