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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
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.
Apr
16
comment Does it take more energy to open a door when applying force close to the hinge?
What is missing here is the part of the applied torque that goes into the inertial forces.
Apr
16
comment Does it take more energy to open a door when applying force close to the hinge?
Theoretically without springs and without friction it takes (almost) zero energy to open the door. Maybe the question needs to rephrased as the energy required to reach a certain rotational speed $\Omega$.
Apr
16
comment if you have an object on an inclined slope, by applying a horizontal force would you be able to lift the object from the slope?
This question lacks a free body diagram illustrating your question.
Apr
15
comment Is this solveable? Simultaneous elastic collision of 4 objects in XY plane
For each collision. Apply it three times (hence the three equations) to get the three unknown impulses. This is nothing new here. Read cs.cmu.edu/~baraff/sigcourse/notesd2.pdf on how to implement algos for multiple collisions.
Apr
15
comment Is this solveable? Simultaneous elastic collision of 4 objects in XY plane
They are not energy equations. They represent the before and after of relative velocity $$v_{final} = -\epsilon v_{initial}$$ See scienceworld.wolfram.com/physics/CoefficientofRestitution.html
Apr
14
comment Is this solveable? Simultaneous elastic collision of 4 objects in XY plane
I had the same concerns but the OP stated in comments that this is really more like a game and not a simulation. The positions are quantized (snapped) to a hex grid so the collision will occur at the same time.
Apr
14
comment Tensions in a rope
Tension is defined as the force you need to apply to a part of the rope so it does not move.
Apr
14
comment Is this solveable? Simultaneous elastic collision of 4 objects in XY plane
For 3D use physics.stackexchange.com/a/92132/392
Apr
14
revised Is this solveable? Simultaneous elastic collision of 4 objects in XY plane
added 193 characters in body
Apr
14
comment Is this solveable? Simultaneous elastic collision of 4 objects in XY plane
I got also $\frac{4}{5} v_A$ for an elastic collision which means the math is probably correct, yet with the impulse method I described you can make the collision inelastic or plastic and also account for different initial conditions.
Apr
14
comment Tensions in a rope
Imagine cutting the rope and holding one side of the cut such as the rope does not move. How much do you have to pull on it? It is 10N, and this is the definition of tension.
Apr
14
answered Is this solveable? Simultaneous elastic collision of 4 objects in XY plane
Apr
13
comment Help calculating work done by stretching a wire
It ain't just a typo when the answer was totally wrong. Thanks for correcting.
Apr
12
comment Help calculating work done by stretching a wire
Check your units. Force and Energy shouldn't have the same units. If $k=\frac{E S}{L_0}$ then $W=\frac{1}{2}k x^2$ and not $W=k x$
Apr
12
reviewed Edit What is the reason behind band gap narrowing in semiconductors
Apr
12
revised What is the reason behind band gap narrowing in semiconductors
added 94 characters in body
Apr
12
comment Truck driven from a small motor that can carry a heavy load, yet can travel fast.
FYI - Use the equations in physics.stackexchange.com/a/15620/392 to model the motion of the truck.
Apr
12
comment Truck driven from a small motor that can carry a heavy load, yet can travel fast.
Try Engineering