Work Energy Theorem: Block on a Slope

Physics Ninja looks at the block on a slope and calculates the speed of the block at the bottom of the ramp using Newton's laws and the work energy theorem.

[@JohnGPagani]

I took "Statics and Dynamics" during summer school at college in 1980. An eighth week intensive summer school program. All the professor's work was on a black board. White chalk only. (1) I enjoyed the pace of your presentation; AND, (2) I enjoyed your graphics.. Thank you.

[@zakwanarif]

Now I understand how to use this method properly. When I checked on other UA-cam video, they tend to neglect the work done by gravity when working on inclined plane problems like this. So I'm getting confused. Anyway thank you very much!

[@shadowkxm]

Perfect explanation. Appreciate it heaps!

[@PhysicsNinja]

Glad you liked it!

[@rubenvegas7926]

I used mechanical energy, where the top had 0 KE and the bottom had 0 PE
Ei+Wf=Ef where Wf is work done by friction
0.5mVi^2+mgHi+(-fk)=0.5mVf^2+mgHf where the initial kinetic energy and the final potential energy are 0, and fk is friction.
Masses cancel, multiply 2 to the left hand side and square root it
Sqrt(2[9.81*0.5-9.81cos(30°)*0.15])=Vf=2.92 m/s

[@yipyiphooray339]

why only Wf? What about the work done by gravity?

[@rubenvegas7926]

@@yipyiphooray339 E initial is the total mechanical energy at point A and B. On both sides i have MGH for the final and initial heights

[@panch2oo2]

I also used energy theory
E (i)= E (f)
MgH= 1/2 MVf^2 + Fr D
3×10×0.5= 1/2×3×Vf^2 + 3.89×1
V f= 2.72ms-1

[@rubenvegas7926]

@@panch2oo2 I think I forgot to zero one term out, otherwise our formulas are the exact same

[@jaydenktan3548]

Excellent applications

[@davidalbigensechilengi]

Great

[@normalperson8066]

You can get the same answer using law of conservation of energy potential energy initial + kinetic energy initial - non conservative force = potential energy final + Kinetic energy final

[@yerimirey]

You kinda made everything too complex more than what is necessary. But still, good video.

[@yipyiphooray339]

Subscribed!!

[@fizixx]

😎