Archive for the ‘Physics’ Category

What is the difference between thermal and internal energy?

Tuesday, October 13th, 2009

extremelyfrustrated asked: According to many sources, internal energy is the kinetic and potential energies of molecules of a substance - combined. Some sources also say that thermal energy is that definition. However, I don't think that thermal energy is kinetic and potential energy combined. I know that heat transfer occurs between ...

What energy changes take place when a ball that is falling through the air reaches its terminal velocity?

Friday, October 2nd, 2009

supercalofragilistic asked: I know that at terminal velocity, kinetic energy remains constant. I know that potential energy decreases because the height changes and air friction against the ball causing heat but I know that is minimal. I really need to know also, where does all that extra potential energy go ...

What is the physical vehicle for transfer of energy in a chemical reaction?

Thursday, September 24th, 2009

AskBrian asked: In an exothermic chemical reaction, how is energy released? Usually it is simply expressed as reactants -> product + energy. But how is that energy emitted? I understand the release of electromagnetic energy through photons, but what other vehicles are there? Do the molecules gain ...

How is potential energy converted to kinetic energy and then heat?

Sunday, September 20th, 2009

M S asked: How is potential energy converted to kinetic energy and then converted to heat?VERNON

How Energy conservation and distructive interference of waves can be justified?

Thursday, September 17th, 2009

saboor asked: when two waves move in same medium and thier resultant becomes zero after destructive interference.what about their there energy.will energy becomes zero?where it goes.ROBERTO

What happens to the energy in living things when they die?

Monday, September 14th, 2009

Chris asked: I don't know much about physics, but I know that energy cannot be created or destroyed. So if this is the case, what happens to all of the energy stored inside, say, a person, if they were to die? Think about it, there's all sorts of like, emotional ...

How can both nuclear fission and nuclear fusion release energy?

Sunday, September 13th, 2009

smilinchick_21 asked: Coming from a chemistry point of view, we are familiar with the concept that making bonds requires energy, and breaking bonds releases energy. So, it follows that fusion should require energy, and fission release energy. However, from a nuclear point of view we know that they both release ...

What are the potential energy and the total energy at time tf?

Thursday, September 10th, 2009

Brenda Y asked: At time ti, the kinetic energy of a particle is 30.0 J and the potential energy of the system to which it belongs is 11.0 J. At some later time tf, the kinetic energy of the particle is 16.0 J. (a) If only conservative forces act on the ...

How much energy is needed to cause a fusion reaction in contrast to how much is released?

Tuesday, September 8th, 2009

Wolfgang asked: The fusion of two hydrogen atoms, for example, releases a large amount of energy. What I need to know is how much energy is needed to start this reaction: is it more than is released, less, or equal to it?TIM

Do solar radiometers rotate the same direction in the northern hemisphere the same as the southern hemisphere?

Thursday, April 30th, 2009

dellostritto@sbcglobal.net asked: The solar radio tester is the fan spinning in what light bulb to be observed. These objects are used in physics experiments. The hemisphere is in reference to the person 's position on the ground that he was controlling the direction of rotation to see if there is ...