If an object is moving at #150 m/s# over a surface with a kinetic friction coefficient of #u_k=15 /g#, how far will the object continue to move?

1 Answer
Jun 7, 2017

Answer:

The distance is #=150m#

Explanation:

The initial velocity is #u=150ms^-1#

The final velocity is #v=0ms^-1#

The distance is #s=?m#

The coefficient of friction is

#mu_k=F_r/N#

Let the mass be #=mkg#

Then

the normal reaction is #N=mgN#

So,

#F_r=mu_k*mgN#

According to Newton's Second Law

#F=ma#

Therefore,

#ma=-mu_kmg#

The acceleration is #a=-mu_kg# , the negative sign indicates a deceleration

The coefficient of kinetic friction is #mu_k=15/8#

We apply the equation of motion

#v^2=u^2+2as#

#0=150^2-2*15/g*g*s#

#s=150^2/30=750m#