Question

If an object is moving at `3 m/s` over a surface with a kinetic friction coefficient of `u_k=20 /g`, how far will the object continue to move?

Answer 1

`S=0.225 m`

Explanation:

`"First; let's calculate the friction force:"`
`F_f=u_k*G`
`G:"weight of object G=m.g"`
`u_k:" coefficient of friction"`

`F_f=u_k*m*g`

`F_f=20/g*m*g`

`F_f=20m`

`a=F_f/m`

`a=(20m)/m " "a=20 m/s^2 " acceleration of object"`

`"when object is stops ,the final velocity of its is zero"`

`v_f^2=v_i^2-2*a*S`

`v_f:"final velocity"`
`v_i:"initial velocity"`
`a:"acceleration"`
`"S:"displacement"`

`0=3^2-2*20*S`

`9=40*S`

`S=9/40`

`S=0.225 m`