A body is moving in a circle with a speed of `1 ms^-1`. This speed increases at a constant rate of `2 ms^-1` every second. Assume that the radius of the circle described is `25 m`. The total accleration of the body after `2 s` is.

Options

A. `2 m s^-2`
B. `25 ms^-2`
C. `sqrt(5) ms^-2`
D. `sqrt(7) ms^-2`

Answer

C

Explanation

( c) `a_t = 2 ms^-2, v = u + a_t t = 1 + 2 xx 2 = 5 ms^-1`
`a_c = (v^2)/( r) = (5^2)/(25) = 1 ms^-2`
Net acceleration =`(sqrt(a_c^2 + a_t^2)) = (sqrt(1^2 + 2^2)) = (sqrt(5)) ms^-2`