A motor car is travelling at 30 m/s on a circular road of radius 500 m. It is increasing its speed at the rate of 2.0 $m/s^2$. Then the acceleration of the car is:

Radial acceleration $a_r = \frac{v^2}{r} = \frac{{\left(30\right)}^2}{500} = 1.8$ $m/s^{-2}$

Tangential acceleration at = 2 $m/se{c}^2$

Resultant acceleration

$a^2 = {a_r}^2+{a_t}^2+2a_r{a}_t\cos \theta$

Here $\theta = {90}^0$

$a^2 = {(1.8)}^2+{\left(2\right)}^2+ 0 = 3.24 +4 = 7.24$

a = $\sqrt{7.24} = 2.7 m{s}^{-2}$