A particle of mass m is projected form ground with velocity u making angle `theta` with the vertical. The de Broglie wavelength of the particle at the highest point is

Options

A. `infty`
B. `(h)/(m u sin theta)`
C. `(h)/(m u cos theta)`
D. `(h)/(m u)`

Answer

B

Explanation

Velocity at highest point `= u sin theta`
`:. lamda_(D) = (h)/(m u sin theta)`
(since `theta` is velocity w.r.t. vertical)