Question

If an object is moving at `120 m/s` over a surface with a kinetic friction coefficient of `u_k=8 /g`, how far will the object continue to move?

Answer 1

`Delta x=900" m"`

Explanation:

`"Object has a kinetic energy due to motion"`
`"The kinetic energy of object is changed to heat energy by"`
`"the friction force"`
`F_f=mu*m*g" "mu=8/g`
`F_f=8/cancel(g)*m*cancel(g)`

`1/2*m*v^2=F_f*Delta x`
`1/2 *cancel(m)*v^2=8*cancel(m) *Delta x`
`1/2*120^2=8*Delta x`
`Delta x=120^2/16`
`Delta x=14400/16`
`Delta x=900" m"`