I have been stuck on a problem for the past hour and after only watching HALF of your video I was able to solve it. THANK YOU!!
@manuboker1 Жыл бұрын
Best physics teacher ever ! Thank you so much :))
@AlePreludioFinal6 жыл бұрын
Thank you so much for doing this videos. Really appreciated!
@waltercampbell43113 жыл бұрын
Ale M. Preve
@kaylasalazar38488 жыл бұрын
please continue to make more videos!! you are the most helpful physics professor on youtube!!
@yoprofmatt6 жыл бұрын
Now that makes me smile, and also a little concerned. Hopefully more talented teachers will get online. Cheers, Dr. A
@NaishaS Жыл бұрын
Would the work done by kinetic friction also equal the change in kinetic energy, so in this case -0.5mv^2?
@myriadoftrouble87206 жыл бұрын
Can you do a problem on energy lost to friction
@matthewa17296 жыл бұрын
How did you teach yourself to write mirror-style so well?
@jacobcaspers62206 жыл бұрын
He is just mirroring the video :D
@mollysolomon61915 жыл бұрын
Im having trouble figuring out how to get the frictional force given delta x and the kinetic friction coefficient. and cos 180
@yoprofmatt5 жыл бұрын
The kinetic frictional force is always fk = μk * N where μk is the kinetic frictional coefficient and N is the normal force. If you're on a level surface, then N=mg. The cos 180 means that the force is opposite the direction of travel, since friction works against you. Cheers, Dr. A
@FasAntick6 жыл бұрын
what about the work you put into an object up to the point where it starts moving on a rough plane?
@yoprofmatt6 жыл бұрын
Excellent! Yes, we didn't consider that in this problem, but somebody had to put work into it to get it moving at vinitial. They had to do work of at least 1/2 mv^2, more if there was friction. Cheers, Dr. A
@vinayakjaiswal57454 жыл бұрын
sir I am INDIAN and this is very helpful for me in LOCKDOWN is also u hit like
@chill_roblox77385 ай бұрын
no i wont hit like
@narendrakumargupta9092 Жыл бұрын
Work done by static friction can be zero,-ve, or +ve. Imagine a two block system one lying over other and a force less than the magnitude of static friction is applied on one block in this case it is not zero. However work done by static friction on a whole system is zero.
@Skkskk7026 жыл бұрын
If we move the same block back to the initial position then why will the total work done by friction force in the round trip be -ve and not 0
@yoprofmatt6 жыл бұрын
It can't be zero because you have to work against friction. If you slide your book across the table and back, you have certainly done work on it. The work that you have done ultimately goes into heat due to friction: the book and the table both heat up. Cheers, Dr. A
@gaafaralkazaaly16634 жыл бұрын
A skier starts from rest at the top of friction-less incline of height 20 m. at the bottom of the incline, she encounters a horizontal surface. Show in figure How far does she travel on the horizontal surface coming to rest
@yoprofmatt4 жыл бұрын
جعفر جبر الخزعلي, Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A
@Ayanakoji257 Жыл бұрын
What is delta x is it distance
@intoxicatedgluestick232 жыл бұрын
LEGEND.
@SangTV_9-21-013 жыл бұрын
Can you help me with this sir? a 6,000-kg car is moving at 10m/s. when the driver steps on the brakes, the car continues to move a distance of 1.2 m until it eventually stops. what is the amount of friction that the road exerted on the car?
@nq78932 жыл бұрын
10 months late, I am only a Junior in highschool (g11). First find the Kinetic Energy (mv^2/2) = 6000x10^2/2) = 300000J. Wnet = Fd, Wnet = Sum of Energy, since on flat ground there is only Gravitational energy. So 300000J = F(1.2m) Ff = -250000N since friciton is opposite direction of displacement. This may or may not be right hope it helps even if it is too late
@user-pu6gp7zp6d8 ай бұрын
i dont get how he's writing on the board and it is not the opposite. I'm confused.
@gallerysagar61624 жыл бұрын
Good😛😛😛
@sugandha88064 жыл бұрын
Work done by kinetic friction is negative it's ok but when we put it positive?
@yoprofmatt4 жыл бұрын
Sugandha, It depends on which side of the equation you put it. Remember, energy is always conserved, just keep track of it. Thanks for the comment, and keep up with the physics! You might also like my new website: www.universityphysics.education Cheers, Dr. A
@nibinkoshy89023 жыл бұрын
if you are asking when the kinetic friction will be positive, you can consider a situation where a body is resting on top of another body, then if the bottom body is moved forward and the top body slides back, then the frictional force on the top body acts along the direction of the motion of the first body and we can say that the net friction work is positive for the top body.
@irtamalik17782 жыл бұрын
Sir does positive friction exist? Example?
@animuszen1362 жыл бұрын
Yes, when you walk you exert a force away from you and onto the floor and the friction against the floor and your foot allows you to move forward. And just to get ahead of the people you are going to question whether or not this is actually friction and not say normal force, note how difficult it is to walk on a surface with a low coefficient of friction like ice.
@zemotika9 ай бұрын
How does he write on the screen like that? Lol wouldn’t it be reversed?? I can’t figure it out 🤣
@nastee417 Жыл бұрын
Static friction can do work, when a box is kept on another box