Question

A body thrown vertically down from a height moves 40 m during the4th second of its motion. Determine its initial speed. (5.7 m/s)​

Answer 1

Answer:

5.7m/s

Explanation:

See the image for solutions

Answer 2

Answer:5m/s

Explanation:Sn=u+g/2(2n-1)

Sn= dist travelled by the body in 'n'th second

u=initial velocity n= given nth second

So from above eqn we get

40= u+ 10/2(2*4-1)

40= u+5(7)

u=5m/s.