The x-acis of a trajectory represents its C
Heat engines are less than 100% efficient because absolute zero cannot be reached
Answer:
The average acceleration of the ball during the collision with the wall is 
Explanation:
<u>Known Data</u>
We will asume initial speed has a negative direction,
, final speed has a positive direction,
,
and mass
.
<u>Initial momentum</u>

<u>final momentum</u>

<u>Impulse</u>

<u>Average Force</u>

<u>Average acceleration</u>
, so
.
Therefore, 
Answer:
~~Now, you have left your question very open ended and didn't ask for any particular kind of answer so I'll do my best to get what you're looking for.~~
A physical change in a substance doesn't change what the substance is. It can possibly melt or freeze an object. I mean heat makes things expand while cooling makes them retract.... In chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.