Very quick question regarding work and kinetic energy

[almosthavoc]

Homework Statement

The question gave a force applied on a block as well as a distance. It also gave the work done by friction which was negative. The question was to find the change in kinetic energy.

Homework Equations

Wnet = change in KE

The Attempt at a Solution

I found the work done by the applied force which is just Fd. Frictional force was already given. My question is do I simply add the 2 works (essentially subtracting from the work done by the applied force) or do I add the absolute value of both?

 

[PumpkinCougar95]

In questions such as this using this is helpful to think

Energy given (Fd) = energy gained(change in kinetic or potential energy ) + energy lost as heat( in this case absolute value of work by friction)

Now this question is really simple so you can just calculate the total Work by numerically adding Work done by Applied force and friction (essentially subtracting), and then equating to change in K.E, But there are problems (For Example related to capacitors) where thinking like this is very intuitive and fast.