# Recent content by alkaspeltzar

1. ### I Conservation of KE, wedge striking ball

nevermind, i see it now. The forces applied to the wedge will cover more distance in the same time than the forces applied to the ball. As a result, there are forces on the ball that make it move away, but the total of the work comes out the same. Darn geometry
2. ### I Conservation of KE, wedge striking ball

You are too deep for me. I just dont see how the work/energy balances out between the wedge and ball. I see the forces, and that makes sense, but when i work it backwards, trying to see how the wedge slows and the ball speed ups, doesnt appear to add up.
3. ### I Conservation of KE, wedge striking ball

reference frames is not my question My questions is the ball feels an equal horizontal force over the same distance as the horizontal force acting on the wedge. The ball should gain KE and the wedge lose KE. But there is a downward force on the ball, over some distance. Where does that work...
4. ### I Conservation of KE, wedge striking ball

you are right, it doesn't change. But that is not the question. My questions is the ball feel a equal horizontal force over the same distance as the horizontal force acting on the wedge. But there is a downward force on the ball, over some distance. Where does that work come from as wouldnt that...
5. ### I Conservation of KE, wedge striking ball

So assume we have a wedge traveling at a constant V horizontally, that is braced so it CANNOT move vertically. Ignore air and friction. See picture. It hits a stationary tennis ball and due to the angle, there is a net force on the ball as shown. The energy should come from the kinetic...
6. ### I How is static friction the centripetal force during a car turning?

No issues, it was a good point as we don't need an engine to make things turn. Any kid with his bike on a big hill can tell you that. As for the verbage confusion, yeah that is my bad. Sorry the friction from the wheel when turning a car to the left(like the picture), creates a rightward force...
7. ### I How is static friction the centripetal force during a car turning?

That is exactly what we were saying and I agree with you. The example above ignores the engine. I am not concerned with propulsive force. I am assuming the car is coasting and you turn the front wheels. Due to the inertia the car wants to continue traveling forward, but the tires don't. There...
8. ### I How is static friction the centripetal force during a car turning?

Interesting to read about the camber thrust and how it really makes sense/supports the outer push on the ground due to friction i was referring to. From there yes the tire deforms and you get the true cornering force as it come back to the vehicle, thru the hub and such. This is helpful. Thank you
9. ### I How is static friction the centripetal force during a car turning?

Thank you Dale for confirming
10. ### I How is static friction the centripetal force during a car turning?

Hello, as you can see i am trying to understand conceptually how the tires during turning create a centripetal force. It was explained to me that as we turn the car tires, the tires similar to a ski or a wedge, now want to push the ground to the side and forward. If the ground was loose, this...
11. ### What makes a door move, the torque or the force or both?

I found the example I posted in my college physics book. I see what you are saying. There has to be force and torque on a door which hangs on hinges. Without net force, center of mass wouldn't move. Without torque, it wouldn't rotate but would move forwards. I kinda think of it like Dale...
12. ### What makes a door move, the torque or the force or both?

A.T., I see the clarification. Yes you are correct. It is always net torque or net force that induces accelerations. You were right, I was being lazy, it easier to explain 1 on 1 when you can work and draw it out. Thanks for hearing me out and like other confirming my thoughts.
13. ### What makes a door move, the torque or the force or both?

Agreed, we need both force and torque for full description and understanding of the motion of the door. But I see now from yourself and others that in rotational motion, it is easier to use/focus on the torque since the forces underway are not clear and/or are changing, at the hinge and such. thks!
14. ### What makes a door move, the torque or the force or both?

Who said I wasn't improving, no need to be rude.
15. ### What makes a door move, the torque or the force or both?

In the link, it shows for a point mass the different is null, you can explain the motion either thru torque or thru force, as one induces the other. Same for the door and your space example. The door would have both rotation and translation, so hence the force moves it forward and causes torque.