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visits member for 4 years, 6 months
seen 10 hours ago

Started programming on a ZX spectrum in the 80's and have moved through Assembly, Turbo Pascal, C++, C#, Fortran. My main area of focus is engineering and scientific computing like numerical methods and 3D graphics.


10h
comment Maximum angle for highway lane change
All season tires will have lower coefficient of friction compared to performance (summer) tires. A minimum of 0.85 can be assumed for most tires.
22h
comment Yaw angle calculation for a two-wheeled inverted pendulum
Hi @JJT. You can use math formatting by enclosing your expressions in $...$. See physics.stackexchange.com/help/notation. It will make your post much more readable.
22h
comment Is rotational motion relative to space?
Is there an experiment we can do to confirm we are rotating about in the milky way? The bulk of matter around is on the milky way and Mach's principle may mean it would be very difficult to measure such rotation.
22h
comment Is rotational motion relative to space?
Related What if the universe is rotating as a whole?
1d
comment Moving Around Space Without Propellant
If it is free floating how is the outer ring not moving? It will move with everything else.
2d
comment Resultant forces on system of particle is zero , we can have?
If you have a pure torque (two separated equal and opposite forces) then angular momentum (and hence energy) is not constant.
2d
comment Friction on a body
Sometimes you must. Try sliding a pot over a hot ceramic stove and you see that the heat creates a low pressure area under the pot making it stick (i.e. increasing friction).
2d
comment Area Moment of Inertia about y axis of i Beam
Except the $(b\tau)(.5h_1+.5\tau)$ term of the op isn't needed.
2d
comment Area Moment of Inertia about y axis of i Beam
For $I_y$ all distances to centroids are zero since you can split this shape up to three rectangles. Top, middle and bottom. All three have centroids along the y axis.
2d
comment Calculating the Precession
"Precession" is not a force (as shown above), but a torque. Actually it is neither as precession is a change in orientation about the first euler angle. Precession, Nutation, Spin being the three euler angles.
2d
comment In which direction does mud fly off a moving bike's tire & why?
@CarlWitthoft the acceleration vector is $$\begin{bmatrix} \dot{v}_x \\ \dot{v}_y \end{bmatrix} = \begin{bmatrix} -\frac{v^2}{r}\sin\theta+\dot{v} (1-\cos\theta) \\ \frac{v^2}{r}\cos\theta-\dot{v} \sin\theta \end{bmatrix}$$ Take the magnitude and see that is is constant when the bike is not accelerating $\dot{v}=0$, with $\| a \| = \frac{v^2}{r}$.
2d
comment In which direction does mud fly off a moving bike's tire & why?
You are confusing the fact that the mud that is most likely to come off (loose mud) will come off first, and the mud that is embedded in the treads will stay stuck for far longer. The riders jersey is there catch only the mud from that location. Mud flung from the top will not land on the rider.
May
18
comment How can I relate linear and angular motion using a single formula?
Actually the op doesn't want a ratio of velocities. The op wants a single (fundamental) equation relating linear and angular quantities.
May
18
comment How can I relate linear and angular motion using a single formula?
You suppose. I still don't know, velocity at which point? Is the velocity of the force application point important to the op? Is the center of rotation point important to the op. If you have a particular situation you have doubts about you can ask your own question so that others have a chance or respond. Note that you shouldn't ask a "Check my work" question, rather you should ask a "How do I approach this situation/concept".
May
17
comment How can I relate linear and angular motion using a single formula?
Are you looking at the same thing exactly? The op question was not clear of what ratio was requested.
May
15
comment Solve $a(t) = g - \beta v(t)$ for $t$
Yes, you direct integration. See answer below:
May
13
comment Is tension always constant throughout a rope of mass in equilibrium?
Is there a fulcrum in the middle of the stick? Maybe a sketch can help clarify things.
May
13
comment Angular momentum with respect to the centre of mass
$I_{cm}$ is the mass moment of inertia tensor. It is defined as $$I_{cm} = \begin{pmatrix} I_{xx} & I_{xy} & I_{xz} \\ I_{xy} & I_{yy} & I_{yz} \\ I_{xz} & I_{yz} & I_{zz} \end{pmatrix}$$ (See farside.ph.utexas.edu/teaching/336k/Newtonhtml/node64.html). It contains the components of inertia for each axis in the diagonal, and cross terms on the off diagonal. As the body rotates (with a 3×3 rotation matrix $E$) the components of $I_{cm}$ change also. This is done with $$I_{cm} = E I_{\rm body} E^\top$$.
May
12
comment Angular momentum with respect to the centre of mass
And Derivation of Newton-Euler equations of motion
May
12
comment Angular momentum with respect to the centre of mass
Related Deriving $\vec{T} = \bar{I} \vec{\alpha} + \vec{\omega} \times \bar{I} \vec{\omega}$