If an object is moving at #20 m/s# over a surface with a kinetic friction coefficient of #u_k=3/g#, how much time will it take for the object to stop moving?

1 Answer
Feb 10, 2016

Answer:

#t=20 s#

Explanation:

#F_f=k*m*g#
#F_f=3/cancel(g)*m*cancel(g)#
#F_f=m#
#F=m*a" The Newton's law"#
#m=m*a#
#a=1 m/s^2#
#v_l :"last velocity ; "v_i:" initial velocity"#
#v_l=v_i-a*t#
#v_l=0 " when object is stops"#
#0=20-1*t#
#t=20 s#