An object with a mass of #5 kg# is moving at #7 m/s# over a surface with a kinetic friction coefficient of #2 #. How much power will it take to accelerate the object at #4 m/s^2?

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Answer 1 · 2017-06-22T12:31:16

The power is #=826W#

The normal reaction is N #=mg=5gN#

The frictional force

# F_r = mu_k # N

The coefficient of kinetic friction is #=2#

#F_r=2*5g N#

Let the force necessary to accelerate the object be #F#

Then,

#F-F_r=m*a#

#F=F_r+m*a#

#=10g+5*4#

#=118N#

The velocity is #v=7ms^-1#

The power is

#P=Fv#

#=118*7#

#=826W#