5 Examples of Solving Centripetal Force Problems - IB Physics 

Yup this is correct. The IB language is weird about this and most problems and the equation booklet write it as tangential velocity rather than speed, so I kept the language even though it's technically incorrect :/

In my example I'm imagining the curve has no friction and the car is pushed to the center entirely by the normal force. A lot of banked curve IB problems don't get more complicated than that so I opted to pretend it was frictionless.

Good question! While there may be a force of friction and/or applied force, the net force has to point straight down at the top so any horizontal force would be cancelled out by another horizontal force, so they're not really important to the problem.

@@AndyMasley oh I get it now, that makes sense. thank you so much!

RIP

@@AndyMasley yep he says with ib converstions he makes the test due dates close so that the test is "harder" and will cause most people to get a worser mark than the actual level 7s He doesn't really teach us...

RIP again brah

did you watch the later examples, they helped me understand!.

Sure yeah! So the normal force is the force applied by a surface to prevent the object from moving through it. On the hill, the car is close to going so fast that it's launched off the top, so it doesn't require the hill to perfectly balance out its weight because it would be going up a bit before coming back down even if the hill weren't there.

@@AndyMasley Right, so if the normal force was the same magnitude as the force of gravity, then the car would be at its max velocity, like you said in the video. that makes it clearer! thanks a lot again! :)

Imagine that you set up a trampoline in your living room, and you jump up very fast and hit your head on the ceiling. When you hit your head, there's no force pushing you up into the ceiling, but the ceiling still reacts and says "nope you're not moving through me" and supplies enough force downward to prevent you from moving through it. This force is the normal force, it points down, and it's created because the surface needs to stop you from moving through it, not because there's some upward force that's carrying you up. With the car example, the car's moving fast enough that if the circle weren't there, it would shoot off into the air instead of moving in a more constricted circle, so the surface also needs to supply some force to keep it in the circle and prevent it from moving through the surface, even though there's no upward force propelling the car. Does that make sense?

@@AndyMasley great explanation, i was searching for it online!

This is incorrect. Any wheel is immobile on its point of contact with the surface it's on. The reason cars don't fall down hills as they move up is that the part of the wheel making contact with the hill is experiencing static friction with the surface, and the friction points up the hill to prevent the car from sliding down. This is very simple HS level physics, there's no debate about this.

And yes, if you can list all the forces on an object moving in a circle, by definition those forces must add together to make the centripetal force. Again this is a simple high school level fact that isn't debated.

Señora no tiene algo mejor que hacer? He podido resolver todos los ejercicios de física gracias a este video. Haga sus propios videos para ver qué tan bien explica usted.

Friction causes the change in motion. If you have a block sliding across a table, friction is causing it to accelerate in the opposite direction of its motion (slow down). In the same way, friction can be the force that causes an object to accelerate toward its center of motion. This is a basic fact of circular motion, it's the reason why cars are able to turn and are unable to turn on ice.

@@AndyMasley ​ As you just said it, Friction can cause change in motion as in the opposite of movement. Friction does not change direction of movement. Change in Momentum however, causes the change in direction, and we may "blame" the friction when we do not know our formulas. As for cars that are able to turn on ice, that's because it is the force in engine that causes the thrust and also the wheel mechanism that causes the change of direction for the tires and these two outside forces make the car turn on ice, while some good winter tires increase the friction so that we need less force to apply to cause that change in direction.

@@AndyMasley You forget that cars move up the hill or turn on ice not because of friction but because of the engine, that creates the force that moves the wheels and Friction is as a result of object moving. Hence, another force is present to cause the movement, not friction.

​@@ardianabani5570 you have a misunderstanding of what forces are and how they apply to cars. It might be helpful to watch a series on force.

@@AndyMasley If you say so. Now all of a sudden you realize that there is not as simple as friction force, Normal and gravity force? Good for you