Example of Energy Transferred Into and Out of a System

[@MrSzybciutki]

I have a question about part c) in 10:23. At the start of the video in 1:39 we said, we're considering only the block to be the system. So shouldn't there be no change in the the internal energy of that 1-body system? The force of friction would be external to the system then. As I understand it, if we considered a 2-body system of block and surface (like @davideveritt1647 said) then the non-conservative force of friction would be internal to that system, and the work done by the force of friction would go into the system as the negative of the change of the internal energy

[@science1878]

i have the same question, did you figure it out?

[@andrewjustin256]

​@@science1878Guys so do I struggle with that! What have both of you found out? Please notify me!

[@named3470]

Well done!!

[@davideveritt1647]

Based on your previous video Energy Systems Clarified, I feel like you should include the level surface as part of the system, here.

[@andrewjustin256]

If Mr. P errored here, and it's true we have to include the surface as our system, then I would to have it confirmed that it wouldn't change any of our calculations right!? Because the problem is not that of the inclined plane.

[@shashwatmishra8441]

why is applied force not a part of the internal energy transfer in part c? isn't an applied force, non-conversative.

[@FlippingPhysics]

Because the system, in this case, is only the wood block. The force applied comes from outside the system. The change in internal energy of the system, the wood block, is in the form of thermal energy. The temperature of the block increases.

[@andrewjustin256]

​@@FlippingPhysicsMr. P you really didn't answer his question!

[@someoneunknown1928]

shouldn't the answer to part c be the net work?

[@Jason-ot6jv]

Do you plan on eventually doing videos other subjects? Maybe some advanced math or engineering? Just a thought!