Question

A body starting from a rest,attains a velocity of 20ms-1.the time taken by the body in the displacement of 50m is?

Answer 1

Given,

u=o

v=20

S=50

t=?

we know,

v2=u2+2as

20^2=0^2+2×a×50

400=100a

a=4m/s-2

again

S=ut+1/2at^2

50=0×t+1/2×4×t^2

50=2t^2

t^2=50/2

t=√25

t=5sec

ans