A block of mass m containing a net positive charge q is placed on a smooth horizontal table which terminates in a vertical wall as shown in figure(29-E2). The distance of the bolck from the wall is d. A horizontal electric field E to towards right is switched on. Assuming elastic collisions find the time period of the resulting oscillatory motion. Is it a simple harmonic motion?

Options

A. `sqrt((4 md)/(QE))`
B. `sqrt(( md)/(8 QE))`
C. `sqrt((8md)/(QE))`
D. `sqrt((md)/(4 QE))`

Answer

3

Explanation

Acceleration `a = (QE)/(m)`
`d = (1)/(2) at^(2) rArr t = sqrt((2d)/(a)) = sqrt((2d)/(QE//m)) = sqrt((2md)/(QE))`
`T = 2t = sqrt((8md)/(QE))`