Question

"for the instant represented, car a has an acceleration in the direction of its motion. car b is moving on a circular path and has a speed vb which is increasing. if the acceleration of b as observed from a is zero for this instant", determine the magnitude of acceleration of a and the rate at which the speed of b is changing

Answer 1

Both the cars would have same acceleration, then only car A is able to see zero acceleration of Car B. This is because, we know that car B is definitely accelerating as it is moving with speed $v_B$ in a circular path. Let the acceleration of Car B be $\alpha_B=v_B/t$, then $\alpha_A=\alpha_B$.

The two cars A and B would have same acceleration i.e. the rate of change their velocities would be equal.