Recent content by Basic_Physics

The problem statement gives the cross sectional area of the drum. So you need to determine what height of a cylindrical shaped amount of water has this weight. I would think that you need to use the density of sea water though for this calculation.

Psychrometric charts This might help: http://www.buildingcontrolworkbench.com/BCWInfo/GrayBook/GPsyctoc.htm

The dB vector is perpendicular to both the ds and r vectors. This means that it points at an angle with respect to the vertical axis on which P lies. So what the problem does is resolve it into two components and then try and figure out what the components are for the various current elements.

You can get the speed of the point by differentiating your fitted equations with respect to time and then using pythagoras to get the resultant speed of the point. This speed can be used to determine the angular velocity of the point. The gradient of the angular speed vs time graph gives the...

The answer is clearly wrong. If the object was placed on the suggested focal point, 3 cm, the image would be real and located at infinity.

θ=ωt

It will be much easier to reconstruct the drawing if you understand the concepts behind it. It is just a convex lens that focusses a set of parallel rays. Question is why is the lens at an angle?

I got that yes, but I don't think the student knows what the circuit looks like. I was trying to make the knowledge step smaller. It seems the students needs more help than in the past.

Galvanometer protection This is for the 2nd case. The two cells oppose each other. The difference in their emfs will drive the current.

In the first instance the galvanometer is connected back to the Daniel cell. So its emf determines the current through the galvanometer. In the second instance the two emfs oppose each other so their difference determines the driving voltage for the current through the galvanometer. Best to make...

One of the neutrons of a carbon-14 nucleus decays into a proton by emitting an electron (beta ray) and an anti-neutrino so that the nucleus now have one more proton - seven in total, but still 14 nucleons. This new nucleus is nitrogen-14, which is stable. To say that an isotope is...

I think you should assume there is no force at D. Maybe it is not a bridge and it is a pulley at end D.

It seems so,yes. I am also not sure if there should be a force at D since it seems you would not be able to solve it if there is a force present at that point.

Yes, I also think so. The structure hinges at A and in order to compensate for its expansion it can roll over the supporting surface at D. The cable is there to raise it.

An unstable isotope means that the specific carbon atoms will change into other elements by emitting radioactive rays. The nuclei of the carbon atoms are unstable and decay into more stable atoms. While the tree was still alive it absorbed carbon dioxide from the atmosphere and the amount of...