Question

The speed of a body is doubled when it moves over a distance of 10m. If the initial speed is 'u' then the speed after further covering a distance of 10m is​

Answer 1

Initial speed is u.

After distance of 10 m ,the speed becomes 2u. Then, from acceleration a=(v^2-u^2)/2s, we have a =3u^2/20 m/s^2 ,because v=2u and s=10m given.Suppose after another 10 m distance, the speed is vf then  vf^2–4u^2=2(3u^2/20)(10). Therefore , vf=(sqrt7)u