The Crow

Hi, I'm the crow. I'm just out of high school. I like Physics

just wondering.....constants are generally rtios between quantities..... How can we 'explain' why a constant has the value it does? It is what it is ... a ratio

there's some nonsense about g of a stationary object being different from that of a falling one. Obviously g is only defined for a body in free fall, not for one eating hot dogs.Sisyphus goes so far as to balance it by the normal reaction. g IS a constant, but does not appear to be one due to the fact that it is always in free fall. About the A+B conundrum, one can say that a is pulling b up, but the reverse is also true. and in fact both forces are internal to the system of falling masses and so dont affect the motion.

Heck, if people want boom, why dont they get stuff like NI3. We made it at our school lab and its pretty cool. Explodes on touch.

Mr. Wilmot has perhaps forgotten that the mc^2 in einstien's relation includes mass energy which is redundant in classical mechanics. The kinetic energy is energy solely due to motion of a body, so it is natural to get it from the quantity that represents amount of motion in a body, that is , momentum. however, momentum is not conserved in presence of net external forces, which is basically present in all mechanics, so the better derivation is by the work-energy theorem.