Question

A body covers 4 m in 3rd second and 12 m in 5th second in uniformly
accelerated motion. The uniform acceleration of the body is??

Answer 1

Explanation:

We know that distance Travelled by uniformly accelerated body in n

th

s is given by

Sn =u+ 1/2 a(2n−1),

where a is the acceleration of the body and u is the initial velocity

it is given that S

n

=4s at n=3

⟹4=u+

2

5a

.............. eq(1)

S

n

=12 at n=5s

⟹12=u+

2

9a

............... eq(2)

solving eq(1) and eq(2), we get

a=4m/s

2

and u=−6m/s

Now we have to find velocity at t=5s

we know that v=u+at

⟹v=−6+(4×5)=14m/s

⟹S=14×3+1/2

4(3^2)=60m

hope this will help you