A rectangle solid box of length `0.3m` is held horizontally , with one of its sides on the edge of a platform of height `5m` . When released , it slip off the table in a very short time `T=0.01` s, remaining essentially horizontal . The angle by which it would rotate when it hits the ground will be `("in radian")` close to:

Options

A. 0.3
B. `0.28`
C. `0.02`
D. `0.6`

Answer

D

Explanation

The block will experience angular acceleration for a very small duration of time
`mgL/2 = (mL^(2))/3 alpha rArr alpha =(3g)/(2L), omega = alpha DeltaT rArr omega = (3g)/(2L) T`
Time taken to reach ground `=(2h)/g=1` sec.
angle rotated, `theta = (3g)/(2L) T rArr theta = (3 xx 10)/(2 xx 0.3) xx 0.01 =1/2 =0.5` rad.