A small block of mass `1 kg` is kept on a rough inclined wedge of inclination `45^@` fixed in an elevator. The elevator goes up with a uniform velocity `v=2 m//s` and the block done not slide on the wedge. Find the work done by the of friction on the block in `1s`. `(g=10 m//s^(2))`

Answer

A

Explanation

`W_(f)=fS cos 45^@`
Here, `f=mg sin theta`, because uniform means net acceleration `=0` or net fore `=0`
`:. W_(f) =(mg sin theta) (S) (cos 45^@)`
`=(1) (10)(S) (cos 45^@)`
if `S=vt =2 xx 1 =2m`

`W_(f) =(1) (10) ((1)/(sqrt(2))) (2) ((1)/(sqrt2))`
`=10 J`.