Question

A car travels forward with constant velocity. It goes over a small stone, which gets stuck in the groove of a tire. The initial acceleration of the stone, as it leaves the surface of the road, is(A) vertically upward (B) horizontally forward (C) horizontally backward (D) zero (E) upward and forward, at approximately 45° to the horizontal

Answer 1

Answer:

A) vertically upward

Explanation:

Since the tyre is rotating with uniform angular speed and moving with constant linear speed

So as soon as a small stone is stuck into the groove of the tyre the speed of the stone is same as that of the tyre

so now we can say that stone will start revolving with the tyre of the car at constant angular speed and moving with uniform speed also

so here just after that the tangential acceleration of the stone must be zero while radial acceleration must be towards the center of the tyre given as

$a_c = \omega^2 R$

so we will have direction of net acceleration is towards its center so correct answer will be

A) vertically upward