Q: A small sphere is suspended by a string from the ceiling of a car. If the car begins to move with a constant acceleration a , the inclination of the string to the vertical is :
(a) tan–1 (a/g) in the direction of motion
(b) tan–1 (a/g) opposite to the direction of motion
(c) tan–1 (g/a) in the direction of motion
(d) tan–1 (g/a) opposite to the direction of motion.
Ans: (b)