A believe that’s called a reference point.
<h2>
Answer:5

,133.6

,51.18

</h2>
Explanation:
Let
,
be the horizontal and vertical components of velocity.
Question a:
Horizontal component of velocity is the ratio of range and time of flight.
So,horizontal component of velocity is 
So,
Question b:
Time of flight=
So,
Maximum height is given by 
So,maximum height is 
Question c:
The vertical velocity is already calculated in Question b.

The answer is C. If the box is accelerating, that means that the amount of force you are exerting is greater than the force of the box.
Answer: ME= E total - E thermal