Physics: Work. Conservation of energy (8)

[pricklypear47]

You should have millions of views. So many beginning physics students could benefit from your lectures. I would be lost in my class without you.



[qusaiw1993]

But we take friction in some exercises

[rafael1877]

why do you get 4 for height???? i dont understand that, everything else i great.

[Kingofallcereal]

@rafael1877 k=4 in the elastic potential energy equation, 1/2*k*x^2. Its not height

[mandygirl777]

@rafael1877 This is because they treated 7m as a height of 0. So for the 11m mark this became 4m

[kosahor]

Thanks for the videos..i made all the mistakes you said some students would make so this really helped..

[WongeneKIM]

Thank you for your lectures!

[savedbylove131000]

why aren't there two kinetic energies for the spring? 

[kosahor]

@savedbylove131000

There arent kinetic energies for the spring because the force along an extended/compressed spring is variable, meaning there isnt constant acceleration meaning velocity changes

[BurntFlower88]

Thank you, very informative!