Question

If a bus is travelling eastwards. Can it’s acceleration be westward? Explain.

Answer 1

It would be called deceleration. Here's why. We have V = U - AT; where U is velocity east and -AT is the deceleration (acceleration in the opposite direction, e.g., west, as shown by the minus sign).  

As you can see, eventually V would become zero; then if -A persists it would increase but in the westward direction as now V = - U - AT < 0 so that the acceleration and current velocity are in the same (west) direction.