Physics 4.7.3a - Friction Example 1

First video in a series of example problems dealing with friction.

[tlema]

Awesome, really nice to have many short examples instead of the typical 30min videos

[auspicious]

These videos are helping me study for my midterm exam. Thank you very much.

[derekowens]

@NaTTyKiinz That's right. m is mass and g is gravity. Specifically, g is the acceleration due to gravity, which is 9.8 m/s^2 or 32 ft/s^2.

[derekowens]

@99miyah Yes, we certainly should. A free body diagram should contain one object and all the forces acting on that object. If there is friction then it should be included. If I didn't do that in this video then that was probably an oversight.

[ShainSz]

very helpful, thank you for uploading !

[jakeor]

thank you. nice one I learned a lot. Keep it up!

[voncyrelersroblesersmondid]

@derek Owen's Elena is trying to move a big cabinet across the floor. The coefficient of static friction on the floor
is 0.5. If the normal force exerted by the cabinet on the floor is 10 N, what is the amount of frictional
force

[OutTryingIt]

continued
but since the friciton is static friction, so wont the engine force F1 be equal in magnitude to the friction. so how can the wheel even move by my concept. where did i go wrong with this? thanks for the help.

having a video for this would really help my friends and me cos we are all struggling with this.

[auspicious]

Do we not label static frictional force on a free-body diagram?

[KillerNWA]

God damn it, why cant you be my lecturer? I learnt more in 4 minutes than in 2 weeks from my lectures xD.

[devipradnya]

i think the normal force not from center of mass but from the interaction of two object... :)

[zerichi]

Anyone?! Someone please help~! Why the 'g' didnt write as -9.81??? Why is it positive????

[OutTryingIt]

Hi derek, could you please do a video on friction covering direction of friction in a driving wheel?i dont understand how it works at all! since my engine turns the wheel in a clockwise, thus at the point of contact with the ground so my friction is forward. but for the wheel to have the rotation and net forward force my friction must be smaller than the engines force (this gives a net force of friction as the engines force will cancel out at the pivot) like this imgur(dot)com/Pw1oh.