Recent content by croad

That was precisely my point. The definition of mass (or volume) would change.

mass = density x volume. In a 2-dim world volume (as it is defined) is zero. How does a body therefore get any mass in a 2-dim world?

Imagine the body rotating in a plane about a point. In a circle. The mass is a mystery though to me, because then the body ought to have infinite density, but perhaps the definition of mass would be different in such a world...

I guess you need to think that e2 = 0e1 + 1e2 + 0e3. Now take the dot product with any other vector you will only get the coefficient of e2 in that vector. Try matrix multiplications if you are familiar, that would help. Matrices are essentially representations of vectors using numbers and gets...

Basically you need to keep in mind that the acceleration and thus the velocity at any distance x (from the center of the moon) is a function of x. This could be derived from GMm/x2. Once you can find the velocity in terms of x you can integrate to find the distance traveled for 12 hrs with an...

It clearly states that the cylinder does not slip, essentially the distance traveled is only by rolling. So just consider the rotational motion.

As far as ferromagnetic core is concerned, magnetic field conduction is better in such a medium than air. Therefore the ferromagnetic core causes higher opposing potential.

Why does increasing the current add resistance? You are correct the strength of the magnetic field increases with the current. But since the current is sinusoidal the magnetic field is not static. Therefore the inductor is now subjected to a strengthened and moving magnetic field which therefore...

I happened to have watch MIT OCW videos on QM. The Prof said that even bucky balls have been shown to show quantum characteristics. Pretty awesome!

Here is an attempt. Look up the definition of each one. Now apply each one to two 3 dimensional vectors. It will be clear. This is just how each one is defined.

I believe you need to know the following A the height of the surface above the hole. In your case you can consider it as distance between the top and the position of the hole. B the area of the hole. A would give you the pressure B would give you the area Multiplying you will get the force...

F = pressure x area = xρg*a (for a sufficiently small hole, so that pressure can be considered constant). mgx = 1/2*mv2 x =v2/2g F = 1/2*v2ρa v is not constant.

Yes that is another way of looking at it. But to explain the acceleration you need to think how the change in velocity occurs. After it becomes zero, momentarily, it starts to go the other direction, without acceleration the velocity will not change. cheers croad

Also think about the time dimension. v=0 only momentarily, when the object cannot go any further and is about to change direction, and starts to travel to the other direction. Without any acceleration the velocity will remain zero and never change, Newton's first law.