Physics 8 Work, Energy, and Power (24 of 37) Sliding down a frictionless incline

This six part physics lecture series will cover the concepts of Work and Energy.

Problem Text:
Johnny costs down a 20m tall hill starting from rest. Assuming no friction, how fast will he be riding at the bottom of the hill?

[MichelvanBiezen]

Seth,
I call it the "conservation of energy" equation.

[sethmamintod]

What do you call that formula again? I can't hear very well

[anasabomoslim]

Great video, but the sound only comes out of the left ear for me.

[mhlengidlomo]

Thanks Sir, but don't the wheels also have rotational kinetic energy

[rolfjohansen]

what if the hill is straight (linear) or circular or another shape, will it affect the terminal speed?

[junczhang]

why isnt there any work done? isnt there a horizontal displacement?

[fizixx]

Great problem, and I'd want to do friction next too. All the different variations one can come up with for these problems is fun, but interesting to see how one thing affects another.

[albertopoli]

I’d have thought that grater mass and greater the

[calebisaac]

Great video Sir, but can i also use the kinematic equation to solve this question?

[chiragsaxena]

Sir, does the equation w+pe+ke=pe+ke+heat lost work for all problems?

[raheome]

Thank you very much for your help sir!

[jeetendrasharma]

Sir, the moving bicycle tyre will also have the rotational kinetic energy as well. Why only translational kinetic energy is accounted for in the analysis of energy equation. Pls clarify.

[eugenekoshanof]

wait a bit, how comes his mass ad the angle of the slope make no difference? Confused

[abumushashah]

If there is energy loss due to friction, then ??

[ahmedal-ebrashy]

I think that was 71 km/hr if I am not mistaken, which is highly unrecommended.

[bryced]

Wouldn't the angle of the hill make a difference? I thought if the hill was steeper, then the person would be going faster at the bottom.