Pair production<span> is a direct conversion of radiant energy to matter. It is one of the principal ways in which high-energy gamma rays are absorbed in matter. </span>
Answer:

Explanation:
<u>Average Acceleration
</u>
Acceleration is a physical magnitude defined as the change of velocity over time. When we have experimental data, we can compute it by calculating the slope of the line in velocity vs time graph.
Note: <em>We cannot see if the time axis is numbered in increments of 1 second, and we'll assume that.
</em>
When
, the graph shows a value of
When
, the object is at rest, 
We compute the average acceleration as




An object is in motion if its distance from another object is changing. An object is in motion if it changes position relative to a reference point. An reference point is a place or object used for comparison to determine if something is moving.
Answer:
Explanation:
She's correct but doesn't mean the wagon cannot put into motion. The force that she applied on the wagon, according to Newton's 2nd law, would have generated an acceleration, which translates into motion. The reaction force the wagon applies on her due to Newton's 3rd law, would not hinder its own motion.
Opportunity cost refers to what you have to give up to buy what you want in terms of other goods or services. When economists use the word “cost,” we usually mean opportunity cost.