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

1 Answer
Apr 7, 2017

The power is #=324W#

Explanation:

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The frictional force is

#F_r=mu_k*N#

The normal force is #N=mg#

So,

#F_r=mu_k*mg#

Resolving in the horizontal direction #rarr^+#

We apply Newton's second Law

#F-F_r=ma#

So,

#F=F_r+ma#

#F=mu_kmg+ma#

#=m(mu_kg+a)#

#=2(3*9.8+3)#

#=2*32.4=64.8N#

The power needed is

#P=F*v=64.8*5=324W#