Question

The initial velocity of a body is 10 m/s. After 5 s, the velocity of the body is 20 m/s. Its velocity after 7 s is ___ m/s.
(i)18
(ii)24
(iii) 16
(iv) 27​

Answer 1

Answer:

its velocity after 7 s is 24 m/s

Answer 2

Given

Initial velocity(u)=10m/s

Final velocity after 5s(v1)=20m/s

Time(t1)=5s

Time(t2)=7s

To find:-

Velocity of the body after 7s(v2)

Solution:-

We know that-----

a=v-u/t

Here----

a= v1-u/t1

a=20-10/5

a=10/5

a=2m/s²

Thus,acceleration of the body is 2m/s².

Now,by using the first equation of motion,we get-----

v2=u+at2

=>v2=10+2×7

=>v2=10+14

=>v2=24m/s

Thus,the velocity of the body after 7s is 24m/s.