A point initially at rest moves along x-axis. Its acceleration varies with time as `a = (6t + 5) m//s^(2)`. If it starts from origin, the distance covered in 2 s is:

Options

A. 20 m
B. 28 m
C. 16 m
D. 25 m

Answer

B

Explanation

`(dv)/(dt) = (6t + 5)`
`int_(0)^(v) dv = (6t^(2))/(2) + 5t`
`v = 3 t^(2) + 5t`
`(dx)/(dt) = 3 t^(2) + 5t`
`x = t^(3) + 5 t^(2)`