Read each staremnt below carefully and state with reasons and expamples if it is true or false ,
(a) with zero speed at an instant may have non-zero accelration at that instant
(b) with zero speed may have non-zero velocity
(c ) with positive constant speed must have zero accleration
(d) with positive value of acceleration must be speeding up.

Explanation

(a) True
When a body is projected upwards then at the highest point, velocity=0, acceleration is equal to acceleration due to gravity and is `9.8 ms^(-2)` vertically downwards.
(b) False. As velocity of the body is the speed in a particular direction . if speed is zero then velocity is also zero.
(c ) True. When a body is moving in a straight line with constant speed then velocity of the body is constant and for constant velocity, acceleration is zero.
(d) False. when velocity is negative and acceleration is positive then body slows down.