A cubical block of mass `sqrt2 kg` is sliding down on a smooth inclined right angled trough as shown in the figure. The two adjacent surface of cube are always in contact with the trough. Then the net reaction force on the block is

Options

A. `10 N`
B. `2 N`
C. `sqrt2 N`
D. `1 N`

Answer

A

Explanation

`N_(1) cos 45 + N_(2) cos 45 = mg` but by symmetry `N_(1) = N_(2)`
`N = (mg)/(2 cos 45) = (sqrt2 xx 10)/(2 xx (1)/(sqrt2))`

`= 10` newton