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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.


Apr
1
comment Is there a systematic way to derive constraint equations?
Welcome to the world of kinematics. Here you parametrize a position coordinate and take derivatives to get to velocity and accelration relationships.
Mar
31
comment Have I calculated the Newtonmeter ($Nm$) of torque for my corded drill correctly?
Use $${\rm Watt} = \frac{2\pi*{\rm rpm}}{60} \cdot {\rm N m} $$ or $$T({\rm N m}) = \frac{30 {\rm Watt}}{\pi {\rm rpm}}$$
Mar
30
comment A block falling from a height on a block suspended by spring
Maybe you need to ask about a specific physics concept, and not ask for help solving a specific problem for you. See meta.physics.stackexchange.com/a/715/392
Mar
30
comment Finding release angle and final velocity of projectile when the target has a different coordinations
The title should be "Design the release angle.." as you want to find the desired angle to hit a target, instead of calculating the actual release angle from current geometry.
Mar
30
answered A block falling from a height on a block suspended by spring
Mar
29
answered Horsepower at certain RPM point without knowing torque?
Mar
29
revised Determining the neutral axis of an I-shaped cross section with dissimilar materials
added 377 characters in body
Mar
29
comment Determining the neutral axis of an I-shaped cross section with dissimilar materials
Note that a bi-metalic part will bend under axial load, and stretch under bending. Modeling it as an equivalent youngs modulus is not going to be accurate. This method can only work with symmetric cross sections that are axially loaded only (like overhead power lines).
Mar
29
answered Determining the neutral axis of an I-shaped cross section with dissimilar materials
Mar
29
comment Determining the neutral axis of an I-shaped cross section with dissimilar materials
Are the parts fixed together, or can they slide past each other. This makes a difference in the resulting strain distribution.
Mar
26
comment Tensor of inertia of a hollow cube
When it comes to 3D, doing the parallel axis theorem by inspection is very tricky. I prefer the vector algebra method shown above with the $[c\times]$ operator.
Mar
26
answered Tensor of inertia of a hollow cube
Mar
26
comment Tensor of inertia of a hollow cube
NVM. Reading again I think I understand. You have the MMOI of thin sheet and you need to assembly 6 of them to form a cube. Is this correct?
Mar
26
comment Tensor of inertia of a hollow cube
The hollow cube is decomposed as a solid cube of side $a$ and a "negative" cube of side $a-2t$ inside it. Since both cubes share the same center of mass I do not see why the parallel axis theorem is needed. Maybe you need to include a sketch in order to understand what the 3D geometry lools like, and about which point is the MMOI taken.
Mar
26
comment Tensor of inertia of a hollow cube
What is the thickness of the cube, and does it have any walls missing?
Mar
26
comment Tensor of inertia of a hollow cube
The center of mass does not change so the parallel axis theorem is not needed. What you need is one positive mass and one negative mass of smaller size.
Mar
25
comment Heuristic equation for Friction force between materials
You can start with just the minimum of the two.
Mar
25
comment Block on block with friction
Related question: physics.stackexchange.com/a/88796/392
Mar
25
answered Acceleration of chairlift
Mar
25
comment friction on a solid body due to another solid body
Block A travels for less time than block B. So the total wear should be the same. Block A may have more wear rate. If any lubrication is present then things change a lot.