If an object is moving at #15 m/s# over a surface with a kinetic friction coefficient of #u_k=225 /g#, how much time will it take for the object to stop moving?

1 Answer
Mar 5, 2016

Answer:

#=1/15s#

Explanation:

we know that frictional force acting on the body while moving in horizontal surface is given by
Kinetic friction #F_k=mu_kmg#,where m= mass and g = acceleration due to gravity
So the retardation a#=F_k/m =(mu_kmg)/m=mu_kg=225/g*g=225 ms^-2#

Initial velocity of the body #u =15ms^-1#
Final velocity v = 0
If time required to stop be t then
#v=u-at#
#=>0=15-225t#
#=>t=15/225s=1/15s#