If a #7/2 kg# object moving at #9/4 m/s# slows to a halt after moving #3/8 m#, what is the coefficient of kinetic friction of the surface that the object was moving over?
1 Answer
Explanation:
We're asked to find the coefficient of kinetic friction
While sliding, the vertical forces (gravitational and normal) cancel out, so we'll look at only horizontal motion to find the friction.
We can use kinematics to find the magnitude of the acceleration, given it went from
We know:

#v_x = 0# (comes to rest) 
#v_(0x) = 2.25# #"m/s"# 
#Deltax = 0.375# #"m"#
Now that we know the acceleration, we can use Newton's second law to find the magnitude of the friction force:
The coefficient of kinetic friction
The normal force
The coefficient of kinetic friction is thus