Honors Physics Unit 5 Review - Energy

[troycampbell]

thank man my awful teacher couldn’t teach me nothing
your a life saver

[richardredic]

I don't like this explanation of Work-Energy or the result found starting around 45 min with the final sled problem. I am only glancing at this, but the Work-Energy theorem states that Work is the change in Kinetic energy. When the kid reached the bottom of the hill, it has more kinetic that at the top - positive work has been done. I agree friction always does negative work, but in this case, gravity does more positive work. The "net" work should be positive. I feel like he's explaining the work term as if it results ONLY from friction... or something. But that wouldn't be correct.