The resistance a surface or object encounters when moving over another.
1
vote
2answers
170 views
Preventing a block from sliding on a plane (with friction)
Assume a small square block $m$ is sitting on a larger wedge-shaped block of mass $M$ at an upper angle $\theta$ such that the little block will slide on the big block if both are started from rest ...
2
votes
1answer
82 views
Approximating Rolling/Sliding in 2D Shape
I'm trying to find more information on how a 2D shape (could be defined by a function, such as ellipse, or by a polygon) will roll across a surface. The shape could be nearly circular or quite ...
0
votes
1answer
158 views
Deceleration of Vehicle off pavement
How would I calculate the deceleration of a vehicle (ATV), wheels locked, on dirt? How long would it take to halt? How fast is it decelerating?
I used this calculator, but it seems incorrect for a ...
6
votes
0answers
98 views
What determines the angle of the cushion on a pool table?
If you look at the cushions (bumpers) on a pool table, you'll see that they're not vertical. They're tilted inwards. About 10 years ago, I came across a physics exam in which one of the problems ...
4
votes
0answers
94 views
Why does the overhand knot jam but the figure-8 knot doesn't?
After tensioning a rope with an overhand knot in it, it is often very hard if not impossible to untie it; a figure-8 knot, on the other hand, still releases easily.
Why is that so? Most "knot and ...
2
votes
0answers
92 views
Why did increasing the Ackermann geometry in my race car make it faster in corners?
Ackermann geometry is used to account for the different radius arcs that the front tires follow when the steering wheel is turned from center. It's often expressed as a percentage: e.g. 25% Ackermann, ...
1
vote
0answers
78 views
What is the angle of the string with the vertical?
A heavy uniform sphere of radius $a$ has a light inextensible string
attached to a point on its surface. The other end of the string is
fixed to a point on a rough vertical wall. The sphere ...
1
vote
0answers
305 views
FPS to MKS usage issues
I'm currently taking a high school physics class and we're doing friction problems now. I've been doing the ones that use MKS perfectly well, but when the problems start to use the FPS system, I'm ...
1
vote
0answers
235 views
Stoke's Drag Constant
I'm trying to calculate Stoke's drag constant using the equation found here.
The system I wish to calculate it for is a mass oscillating vertically on a spring through air. The temperature is 25 ...
0
votes
0answers
73 views
Describing the movement of the object in a particular situation in Lagrangian way
Suppose there is a object M, (sliding motion) moving by the initial speed $v$ and the initial location $x_0$. Otherwise noted, friction is assumed to be nonexistent. It then meets a circular mold ...
0
votes
0answers
107 views
A problem on mechanical energy and friction
I'm studying for a mid-term, and I'm trying to solve some mock-papers. The following are two problems which I have solved, but I'm missing a part:
$(1)$ A body of mass $ m_1= 8 \rm kg$ passes ...
0
votes
0answers
348 views
Reynolds Number and relation to Moody Diagram for a Small Pipe
I am having the following problem on a lab write up:
Calculate the approximate distance downstream of the inlet that
corresponds to the hydrodynamic entry length for Reynolds numbers of
3,000 ...
