Question

Q8)A body is moving with uniform
acceleration travels 100m and 120m
respectively in 5s and 10s .initial
velocity of body should be equal to-​

Answer 1

Given :

The distance covered in 5 seconds = 100 m

The distance covered in 10 seconds = 120 m

To find :

The initial velocity of the body .

Solution :

Let the initial velocity of the body be u and the acceleration be a .

according to the second equation of motion ,

s = u * t + ( 1 / 2 ) * a * t * t

where , s is displacement ,

u is initial velocity ,

a is acceleration ,

and , t is time .

now ,

100 = 5 * u + ( 25 / 2 ) * a          .....(i)

120 = 10 * u + 50 * a                  ......(ii)

on multiplying (i) by 4 and subtracting (ii) from it ,

280 = 10 * u

=> u = 28 m/s

The initial velocity of the body is 28 m/s .