State which of the following situations are possible and give an example for each of these: 

(a) an object with a constant acceleration but with zero velocity 

(b) an object moving with an acceleration but with uniform speed. 

(c) an object moving in a certain direction with an acceleration in the perpendicular direction

(a) Possible. 

Let a ball be thrown in vertically up with some initial speed u. After some time its velocity decreases and at the maximum height, its velocity will be zero but it has a constant acceleration (9.8m/s²) in the downward direction due to gravity. 

(b) Possible. 

When a body is moving in a circular path with constant speed, it is accelerating due to change in direction of motion.

(c) Possible. 

Let a stone is tied at its end with a string and is whirled in horizontal circular motion with the other end of the string. It has centripetal acceleration pointed towards the center. Hence the acceleration is perpendicular to the motion of stone.