Home > Physics > Power

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 #8 m/s^2?

Answer 1

Amelia Adams

The power is #=374W#

The frictional force is related to the normal force

#F_r=mu_k*N#

#N=2gN#

#mu_k=3#

#F_r=3*2g=6gN#

To accelerate the object, we need the force, #F#

We apply Newton's second Law

#F-F_r=m*a#

#a=8ms^-2#

#F-6g=2*8=16#

#F=16+6g#

The power is related to the velocity

#P=F*v#

#v=5ms^-1#

#P=(16+6g)*5=374W#

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Emily Abbate

The power required to accelerate the object at (8 , \text{m/s}^2) is (34 , \text{W}).

By signing up, you agree to our Terms of Service and Privacy Policy

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.