A microwave oven of mass 13.0kg is pushed a distance 8.80m up a ramp

[nouvelague]

Homework Statement

A microwave oven of mass 13.0 kg
is pushed a distance 8.80 m
up the sloping surface of a loading ramp inclined at an angle of 38.3 ∘
above the horizontal, by a constant force F⃗
with a magnitude 150 N
and acting parallel to the ramp. The coefficient of kinetic friction between the oven and the ramp is 0.240.


Part D
Use your answers to parts (A), (B), and (C) to calculate the increase in the oven's kinetic energy.
Take the free fall acceleration to be 9.80 m/s2
. Express your answer using two significant figures.

Relevant Equations

W = change in KE
-change in U + Wfriction = change in KE

For this one, am i supposed to use W = change in KE where i calculate work as ((F - friction - mgsintheta) times d), or am i supposed to do the change in -mgh plus Wfriction = change in KE (where if it is in this case, is the friction going to be a negative number?)

 

[kuruman]

Since friction is involved, you are supposed to use the kinetic energy theorem $$\Delta (KE)=W_{\text{net}}.$$ I assume that in the previous parts you have calculated all the works that are needed.

 

[haruspex]

where if it is in this case, is the friction going to be a negative number?

Will the friction occurring here increase or decrease the kinetic energy?