Recent content by TomHart

Just to clarify one thing for @Biker, there is no normal force exerted by the wall on the wheel if the wheel leaves the ground. If the wheel remains on the ground, the friction force from the ground to the wheel will produce a normal force from the wall to the wheel. @kuruman, would you please...

Is it even possible for the wheel to roll up the wall (well, except for one very unique acceleration)? How can the wall apply a friction force to the wheel once the wheel leaves the floor? Is there a normal force from the wheel to the wall? Or am I confused again? :)

Yes, both must have maximum friction in accordance with their normal forces.

If rolling without slipping is possible, that requires that the disk lift up off the ground. So how can you have any friction at A when it is rolling up the wall?

From the figure, it looks to me like the angle is 37 degrees, not 137 degrees. I think what is being interpreted as a "1" is actually the angle indicator - the same as is the case in Figure 1.

When I was young, I had excellent near vision. Now . . . not so much. However, even when I downloaded the photo and zoomed in, I can still see well enough to realize there is a shortage of pixels; it is still very difficult to read. "And things that are too hard just aren't worth doing,"...

Please double-check that equation; it isn't quite right. And you are correct that v = x/t does not apply if there is acceleration. Edit: Oh, I thought I was responding to the original poster. Oh well, I guess I'll stick with my response. :)

Welcome to PF. It looks like you found α = 41.5. That would have been true if the specified velocity change occurred within 1 second. But it took 15.7 seconds.

I think so.

Working it out very quickly, and thus prone to error, I think the first answer is correct.

Your equation is appropriate. If you know fbeat (which you do), and you know f1 (which you do), there are only 2 possible solutions for f2.

Have you ever tuned an instrument? I will assume that you have not. If you have two instruments (whatever they are - flutes, guitars, digitally generated sine waves, etc.), and you strike a sound on each of them, if the frequencies of those two sounds are slightly different, you will be able...

That is incorrect also. That is 4.28 to the 14th power. Maybe you could try 4.28e14. That is fairly standard. Edit: That is standard notation for 4.28 x 10^14.

That is the speed of light. Light travels at 300,000,000 meters per second (m/s). (Actually, if I remember correctly, I think the exact speed of light is 299,792,458 m/s.) So if your answer of 4.2857143 x 10^14 is wrong, you may want to consider trying a more exact value for the speed of...