A vehicle runs on a straight road of length 'L'. It travels half the distance with speed V and the remaining distance with speed $\frac{\mathrm{V}}{3}$. Its average speed is

The following figures show the variation of displacement with time of a particular object.

A velocity - time graph of a body is shown below. The distance covered by the body from 6 second to 9 second is

The ratio of weight of a man in a stationery lift and weight when the lift is moving downward with a uniform acceleration ' $a$ ' is $3: 2$. Then the value of ' $a$ ' is