Recent content by Eugbug

Has anyone ever built an internal combustion engine which runs on solid fuel? A system would have to use waste heat or a mechanical friction device or whatever to heat the fuel and produce vapor which would be burnt in the cylinder (similar to the way coal gas was produced). Of course the vapor...

Well the force at the axle is 2F since the clockwise moment = the anticlockwise moment. So the acceleration is 2F/m. There is no torsion reaction force at the point of contact between the wheel and ground since the "lever" is free to move. So the reaction is simply the inertia of the mass...

In the diagram attached, a force acts tangentially on the edge of a wheel. To make things easier, the wheel is massless, so moment of inertia doesn't need to be taken into account. However there is a concentrated mass M at the axle(It could be taken as the mass of the axle). Two equal but...

Can someone explain what exactly happens when a capacitor is charged? At the positive plate, are loosely bound electrons pulled onto the plate from the dielectric or are whole molecules in the dielectric rotated and orientated so that the negative part of the molecule is close to the plate? Why...

At the atomic level, close to the surface which is creating the sound, is it the case however that molecules in the air are being accelerated by the vibrating surface and they reach a velocity higher than that of sound because of the motion of the vehicle, even though the wave propagates at the...

When an object is thrown out from the front of a vehicle, its initial velocity relative to the ground is the velocity relative to the vehicle plus the velocity of the vehicle. Why is this not the case with sound traveling out from the front of a jet for instance? Or do the velocities add...

I have forgotten most of my chemistry at this stage but is it possible that the electrons could combine with the phosphor and ionize it or add to the phosphor molecules and create a new compound. What happens for instance when the screen is "burnt" by the beam?

Appliances which behave as a resistive load, eg kettles, toasters, electric fires (without fans), kitchen ranges etc, can in theory be run on DC. DC generates the same heating power as AC with the same voltage once the AC voltage is quoted in RMS. In practice however, switches in these...

Do electrons flow in a "circuit" in a CRT? When they hit the phosphor coating on the screen, does the final anode complete the circuit and allow current to flow back to the circuitry or does the anode only serve to accelerate the electrons which then "accumulate" by combining with the phosphors...

The inspiration for this question came about when I was coming down a mountain at top speed on my mountain bike and was thinking about how braking works on a wheel and whether a skid can occur if enough braking force is applied and the wheels don't actually lock. To make things simple, take a...

If an axle is being pulled with a tractive effort E, can this be resolved into a couple and forwards force E at the point of contact with a surface? Is it correct to add a limiting friction force F acting backwards against the direction of motion and if this is exceeded by E, does the wheel slip?

Thanks for the answer Philip! I was reading a question about Bungee ropes last night on Webanswers and this equation could probably go some way towards modeling the behavior of a jumper when they have reached the end of the rope which then starts to stretch.

For a harmonic oscillator with mass M, spring of stiffness k and displacement the force equation is: -kx = Md2x/dt2 How do you handle the situation and work out a solution for x(t) when the mass has an initial velocity. E.g. a mass dropped onto the spring?

I just want to confirm an error I have seen on another website about discharging of batteries. The poster suggested that the mass of a battery decreases because matter is being converted into energy according to the equation E=mc2 as the battery discharges. They said that because c is so large...

When the door is moved close to the magnet and is let go, the magnet does work as it moves the mass of the door through a distance. That is the definition of work. The energy to do this must come from the magnet. Presumably the same thing would happen if a distant object is moved into the...