All Questions
Tagged with rotational-kinematics friction
58
questions
24
votes
6
answers
5k
views
Conical train wheels
I've been reading about how the conical shape of train wheels helps trains round turns without a differential. For those who are unfamiliar with the idea, the conical shape allows the wheels to shift ...
- 642
8
votes
5
answers
2k
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Conservation of energy of 2 identical Rolling Disks with and without friction
My physics book claims that if two identical disks moving at the same velocity travel up nearly identical hills, with the second hill not having friction, then the disk rolling up the first hill will ...
- 81
7
votes
1
answer
3k
views
Does a tire need to slip to generate force?
Recently, I have been doing some research on racing and tire modelling. While I was doing this, I encountered many curves like those shown below.
(source: insideracingtechnology.com)
While I ...
- 427
6
votes
4
answers
4k
views
Why do office chairs rotate when pushed/pulled out?
A common source of frustration when I'm at work is the fact that my rolling office chair's wheels rotate whenever I push it forward or backward from my desk, which can cause it to bump my computer ...
- 162
5
votes
2
answers
9k
views
The direction of frictional force in circular turning
Why does the frictional force in case of circular motion point towards the center even though the motion is tangential to the radius?
- 997
5
votes
3
answers
385
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Why does it get harder with time, to rotate a screw with a screwdriver?
A couple of forces act on the machine screw and create the turning effect. But after sometime it gets harder. So, net torque is decreasing, but why is it decreasing? Frictional force comes into action,...
- 177
3
votes
2
answers
540
views
Energy loss due to friction in Rolling Motion
I understand why rolling motion does no work. My (possibly imprecise) summary of the answer is that net work done is zero. And the role of friction is to convert translational kinetic energy into ...
- 347
3
votes
3
answers
447
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Why is the direction of friction different in case of rolling on plane surface and on an inclined plane?
I was studying the rolling of spherical objects on plane surfaces and inclined planes. I had doubts about the direction of friction in both cases.
Case 1-
In the first case i.e. rolling on the plane ...
3
votes
4
answers
8k
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In which direction does friction from the ground act on the wheel?
When a bicycle wheel is in motion, many forces are acting on it. The sum of the forces results in forward
motion. In which direction does friction from the ground act on the wheel?
- 212
2
votes
5
answers
24k
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Acceleration of body rolling down inclined plane
Acceleration of a body rolling down an inclined plane is given by:
$$\frac{g\sin\theta}{1+\frac{k^2}{r^2}}$$
$g$=acceleration due to gravity
$\theta$=angle of inclined plane
$k$=radius of gyration
...
- 711
2
votes
1
answer
136
views
Can a torque on the rim of a solid cylinder cause rolling without slipping?
I'm getting stuck on friction (heh). Here's a simplified problem from my textbook illustrating my confusion.
We have a solid cylinder of mass m and radius r, lying on its side on a table, with a ...
- 305
2
votes
1
answer
98
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Problem on rotation
So this is the problem:A wheel of radius of gyration k is placed on a belt moving with a speed v, which is maintained constant by means of an external agency. Assume that the axis of the wheel is ...
- 235
2
votes
3
answers
882
views
Why does friction not accelerate a wheel?
It seems like a silly question because this defies common sense, but it appears that friction is supposed to accelerate a wheel (not attached to anything).
We can derive from Newton's laws that $\...
user113773
2
votes
3
answers
71
views
Is there a reference frame in which the static friction from rolling does positive work?
I am worried this will be deleted as a duplicate question, so I will try to be extra clear what I am asking:
In some reference frames, static friction can do positive work. If you have a crate in the ...
- 21
2
votes
1
answer
2k
views
Maximum friction force for a wheel to be able to roll [duplicate]
The wheel with mass $M$ and radius $R$ below is free in space (it is not on the ground). A torque $\tau$ is applied to it through an engine. A horizontal force $F = \frac{\tau}{R}$ is also applied to ...
- 115