Suppose that water drops are released from a point at the edge of a roof with a constant time interval `Deltat` between one water drop and the next. The drops fall a distance h to the ground. If `Deltat` is very short ie the number of drops falling through the air at any given instant is very large then the CM of the drops is very nearly at a height (above the ground ) of

Options

A. `h//2`
B. `h//3`
C. `2h//3`
D. `3h//4`

Answer

C

Explanation

The droplets fall a distance `(1)/(2)g t^(2)` in time t, and the number of the droplets and hence their mass is proportional to `dt`. Computing the CM of the droplets using the definition, we get the result.