>>14250733During an interaction, there's a point where both things are at the same velocity. If a ball hits a car, it changes directions, so at some point they're the same. If you through something up and it falls, at some point its speed was zero.
Don't start your question with why in science. Observe and rule things out. Did two things become one thing? No. Did they change what they were doing? Yes. Did something else cause the change? No.
One thing pushed back on another. That energy came from elastic material like the car and ball, or changes in internal clockspeeds like with gravity.
