Rörelsemängd - lastbil krockar med pingisboll?
A heavy truck collides with a ping pong ball that has been thrown into the air. The truck drives at a speed of 50
km / h and collides with the stationary ball. The collision is elastic. What speed does the ball get right after the
crash?
I have thought that because the crash is elastic, both the momentum and the kinetic energy are preserved. I assumed that the truck's speed was the same before and after the crash. When I set up the equation, it becomes; m1v1 = m1v1 + m2v2 but this can hardly be true. Then I also assume that the task can be solved without producing numbers and only with the help of variables and info from the task. Help!
https://www.pluggakuten.se/trad/rorelsemangd-lastbil-krockar-med-pingisboll/
Use google translate (if you have not already done that...).
The problem is that you anticipate the truck's speed is the same before and after the collision. That can only be true if energy is added to the truck (for example via the trucks engine). You must anticipate that the trucks engine is not active during the collision.
