A body covers `100cm` in first 2 seconds and `128cm` in the next four seconds moving with constant acceleration. Find the velocity of the body at the end of 8 sec?

Explanation

In first 2 seconds
`100=2u+(1)/(2)a.4……(1)`
In first 6 seconds
`228=6u+(1)/(2)a.36rarr(2)`
`(1)xx3-(2)" gives "72=-12a`
`a=-6cm//s^(2)......(3)`
`100=2u-(1)/(2)xx6xx4`
`2u=112`
`u=56cm//s......(4)`
Now velocity of body at the end of 8 sec is
`V=u+at=56-6xx8`
`therefore V=8cm//s`.