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An object with a mass of #8 kg# is moving at #5 m/s# over a surface with a kinetic friction coefficient of #6 #. How much power will it take to accelerate the object at #3 m/s^2?

Answer 1

Charlotte Aaron

The power is #=2472W#

The normal reaction is N #=mg=8gN#

The frictional force

# F_r = mu_k # N

#F_r=6*8g N#

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

Then,

According to Newton's Second Law

#F-F_r=m*a#

#F=F_r+m*a#

#=48g+8*3#

#=494.4N#

The power is

#P=Fv#

#=494.4*5#

#=2472W#

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Answer 2

Lily Adams

To calculate power, use the formula: ( P = F \cdot v ), where ( F ) is the force required, and ( v ) is the velocity. The force can be determined by ( F = m \cdot a_f ), where ( m ) is the mass and ( a_f ) is the net acceleration (considering friction). First, find ( F ) using ( F = m \cdot (a + a_f) ), then substitute into the power formula.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.