It's inertia. A rule that you see every day, for example a brick will stay in the same spot unless a force acts on it.
The answer for this question is Control Variable because it doesn’t change throughout the experiment.
Mem me e m even have. Jags. Shah. Shiv side esicjm is n meh dish so do indbbd
This being a perfect collision means no energy is lost during the collision. Because this question asks for speed and not velocity, the speed will be the same because the final energy is the same. The speed after the collision would therefore be 1.27 m/s.