State whether the following cases can occur in real life. If possible, give one example for each:

(a) A body has constant acceleration but zero velocity.

(b) A body is moving in one direction while its acceleration acts at right angles to that direction.
a. It is
 
b. It is
 
Example:
Answer variants:
An object thrown up into the air
An object moving in straight line
An object accelerating in a circular trajectory
An object accelerating in trajectory
Case - a 
Case - b