Question

As a stop light changes from red to green, a car starts to cross through the intersection. An instant before it begins to move, its velocity is zero. Must its acceleration at that time also be zero. Why or why not

Answer 1

Yes, the acceleration at that time is also zero because the velocity is zero.

Step-by-step explanation:

To answer the question given above, we shall determine the acceleration of the car at time 't' when the velocity is zero.

From the question given above, the following data were obtained:

Velocity (v) = 0 m/s

Time (t) = t

Acceleration (a) =?

Acceleration is defined as:

Acceleration (a) = Velocity (v) / time (t)

a = v/t

a = 0/t

a = 0

From the above illustration, we can see that the acceleration is zero irrespective of the time 't'.

Therefore, the acceleration of the car will be zero since the velocity of the car at time 't' is zero.