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visits member for 3 years, 5 months
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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.


1d
comment Lateral forces on earths surface
If the giant sphere was resting on a frictionless surface then it would appear as if it was spinning in place.
1d
comment Coordinate System vs. Angular Properties vs. Centroid
Yes, 3D dynamics and kinematics are straight forward if you get all your ducks in a row, but there are a lot of ducks to account for.
1d
comment $\psi^*$ if you have sine or cosine function
@JamalS is it? You can have $\sin(\hat{i}) = \hat{i} \left( \frac{\hat{e}}{2} - \frac{1}{2 \hat{e}} \right)$. I think the answer is it depends on what $x$ is.
1d
comment $\psi^*$ if you have sine or cosine function
I think this is valid question for Mathematics. "What is the complex conjugate of a sine function?"
1d
comment Coordinate System vs. Angular Properties vs. Centroid
See related post physics.stackexchange.com/a/95542/392 if interested in the subject.
1d
revised Coordinate System vs. Angular Properties vs. Centroid
added 216 characters in body
1d
answered Coordinate System vs. Angular Properties vs. Centroid
1d
comment How long does it take for an electric car to go from 0 to 60 mph?
@jumpjack you are doing something wrong then. It is time to create a new question with the above, and show your work.
Apr
12
comment Describing a motion of gyroscope with gimbal
What I am missing above is the torques at the joints which accelerate the gimbal. Their result goes into joint moments $$\vec{\tau} = \hat{i} \tau_1 + E_1 \hat{j} \tau_2 + E_2 \hat{k} \tau_3$$
Apr
11
revised Describing a motion of gyroscope with gimbal
added 189 characters in body
Apr
11
answered Describing a motion of gyroscope with gimbal
Apr
11
comment How long does it take for an electric car to go from 0 to 60 mph?
You can get $x(v)=\int \frac{v}{a}\,{\rm d}v$, but you wont be able to invert it I think. Try it.
Apr
10
comment How long does it take for an electric car to go from 0 to 60 mph?
@jumpjack read the FAQ on homework type questions. No complete answers are not allowed.
Apr
9
comment How long does it take for an electric car to go from 0 to 60 mph?
I gave you the tools to do the work yourself. This is how this site works. As far as torque goes, no manufacturers give torque at engine/flywheel always.
Apr
9
comment How long does it take for an electric car to go from 0 to 60 mph?
See now? I have been telling you for days, that this is the correct way of doing it. In your case you may need simulate small speed increments and calculate time and distance from there. Kind of like an numerical ODE solver.
Apr
9
comment How long does it take for an electric car to go from 0 to 60 mph?
$E = P t$ is wrong since $P$ is not constant. It is $E = \int P dt$ stated correctly.
Apr
9
comment How long does it take for an electric car to go from 0 to 60 mph?
$a = \frac{dv}{dt} \} dt = \frac{1}{a} dv \} t = \int dt$ It is not wrong, it is called direction integration. Look it up.
Apr
9
comment How long does it take for an electric car to go from 0 to 60 mph?
You are using torque and engine, and wheel radius. You need to transfer the torque to the wheels. You need gearing information (I do not suppose it is a direct drive). Use $T=\frac{P}{v} r$ to get torque at wheel and $gear = \frac{T}{T_{engine}}$.
Apr
9
comment Hanging a brick free over an edge by stacking them
Yes for only one brick over the purple one $F=\frac{1}{2}W$, but I was calculating when four bricks are over the purple one (7 total).
Apr
9
answered Hanging a brick free over an edge by stacking them