- #1
Robin04
- 260
- 16
Hi,
I'm reading a high school textbook about mechanics. It's amazing how the author draws up the problems and solves them by introducing a new consistent concept.
Now I'm reading about collisions. He writes the conservation of momentum but the problem is that we have two unknowns in one equation so another one is needed. He defines beautifully the concept of elasticity by analyzing the bouncing of a ball dropped from a certain height (with geometric sequence) thus solving the problem, we have the second equation. With some simple math he changes it to a form which is very close to the conservation of kinetic energy (only the 1/2-s are missing) then he states that by taking the half of mv^2, so 1/2 mv^2 we get a new notion which is the kinetic energy. I don't really get this part, I feel he's missing something or there's another way to get to the kinetic energy. He doesn't say anything about why we have to multiply the terms (that we got from a very logical thought) with 1/2.
Thanks for you help! :)
I'm reading a high school textbook about mechanics. It's amazing how the author draws up the problems and solves them by introducing a new consistent concept.
Now I'm reading about collisions. He writes the conservation of momentum but the problem is that we have two unknowns in one equation so another one is needed. He defines beautifully the concept of elasticity by analyzing the bouncing of a ball dropped from a certain height (with geometric sequence) thus solving the problem, we have the second equation. With some simple math he changes it to a form which is very close to the conservation of kinetic energy (only the 1/2-s are missing) then he states that by taking the half of mv^2, so 1/2 mv^2 we get a new notion which is the kinetic energy. I don't really get this part, I feel he's missing something or there's another way to get to the kinetic energy. He doesn't say anything about why we have to multiply the terms (that we got from a very logical thought) with 1/2.
Thanks for you help! :)