10,057 reputation
21744
bio website
location United States
age
visits member for 4 years, 5 months
seen 40 mins 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.


Apr
21
comment Large deflection of cantilever beam
Do you measure deflection along a fixed axis, or does it follow the arc of the end of the beam?
Apr
21
comment Instant centre of rotation for two connected gears
Is O fixed in space and A orbiting around?
Apr
20
comment Energy needed for Superman to take off and fly at the speed of sound
From your first two statements you have $4.0 + 0.2 = 4.8$ ????
Apr
20
answered Object Pushed by Multiple Forces
Apr
20
comment Object Pushed by Multiple Forces
When dealing with dynamics we are compelled to choose the center of mass or else the equations of motion won't work. See physics.stackexchange.com/a/81078/392
Apr
20
comment Superposition of accelerations in multibody problem
$a_1+a_2 + \ldots = a_{net}$ is not a fundamental law of anything.
Apr
20
answered Superposition of accelerations in multibody problem
Apr
20
comment Can someone explain this solution for the motion of a falling chain?
How can I perform an experiment with an ideal chain with ideal conditions? I have observed ropes, chains and wires unfold due to gravity and I stick to me answer unless proven otherwise.
Apr
19
comment Compression in a sphere due to a sectoral load?
Note the theoretical deformation of a line load (force on circumferance) is infinite. You have to consider a certain pressure width to be able to apply Hertzian or non-Hertzian contact properties.
Apr
19
comment Compression in a sphere due to a sectoral load?
Since the loading is not uniform (only convers part of the surface) you need to solve the Bussinesq energy integrals your self and there is no guarantee that there is a numetically stable solution either. At this point I recommend going the FEA way.
Apr
17
comment Does it take more energy to open a door when applying force close to the hinge?
The force needed to accelerate the center of mass.
Apr
17
comment Can someone explain this solution for the motion of a falling chain?
2) Tension affects the center of mass of the falling size, but also the center of mass of the stationary side (since more and more of the chain becomes stationary). The net result is zero.
Apr
17
comment Can someone explain this solution for the motion of a falling chain?
1) If the chain is falling on the right side, after it whips it is going to be rising on the left side. That horizontal motion is going to carry kinetic energy but only for a negligible fraction of time. After that is going to loose all horizontal motion. So when looking at before and after only the vertical motion accounts for change in kinetic energy.
Apr
17
comment One force applied to one point of a rigid body: centre of mass and torque
See Do objects rotate around the torque vector or its center?
Apr
17
comment One force applied to one point of a rigid body: centre of mass and torque
See Derivation of Newton-Euler equations of motion
Apr
17
comment One force applied to one point of a rigid body: centre of mass and torque
The correct equation is $$\vec{\tau} = \frac{{\rm d}I \vec{\omega}}{{\rm d}t} = I \vec{\alpha} + \vec{\omega} \times I \vec{\omega} $$
Apr
17
revised One force applied to one point of a rigid body: centre of mass and torque
math formatting
Apr
17
comment Schrödinger Equation
Are you trying to establish a physical interpretation of a wavefunction on a human scale?
Apr
17
answered Can someone explain this solution for the motion of a falling chain?
Apr
17
comment How to calculate the normal force exerted by a fulcrum off-center?
There must be another support, or the rod would move (tilt). The answer differs depending on the situation.