An object with a mass of #5 kg# is moving at #4 m/s# over a surface with a kinetic friction coefficient of #4 #. How much power will it take to accelerate the object at #3 m/s^2?

1 Answer
Feb 8, 2018

The power is #=844W#

Explanation:

The mass of the object is #m=5kg#

The initial velocity is #u=4ms^-1#

The acceleration is #a=3ms^-2#

The coefficient of kinetic friction is

#mu_k=F_r/N=4#

#F_r=mu_kN#

The acceleration due to gravity is #g=9.8ms^-2#

The normal force is

#N=mg=5g#

In order to accelerate the object, Apply Newton's Second Law of Motion

#F-F_r=ma#

#F=F_r+ma=4*5g+5*3=211N#

The power is

#P=Fv=211*4=844W#