A body rolled on ice with a velocity of `8 ms^(-1)` comes to rest after traveling a distance of 4m for this situation which of the following pair is correct

Options

A. acceleration =+8 `ms^(-2)` coefficient of friction =0.8
B. aqcceleration =+4 `ms^(-2)` coeffiecient of friction =0.4
C. accelearation =-8 `ms^(-2)` coefficient fo friction =0.816
D. acceleartion =-`16ms^(2)` coefficent of friction =1.62

Answer

c

Explanation

`u=8 m//s , v=0 0,s =4m , a= ?`
`v^(2) -u^(2) = 2 as`
`0^(2) -8^(2) =2a xx 4`
`-64 =8a`
`a= (-64)/(8) =-8ms^(-2)`
`a= |-8| = 8 ms^(-2)`
Coefficient of friction `mu= (f )/(r ) =- (ma)/( mg)`
`(a)/(g) = (8)/(9.8) = 0.816`