The correct answer is
<span>c. one person exerts more force than the other so that the forces are unbalanced.
In fact, the door is initially at rest. In order to move the door, a net force different from zero should be applied, according to Newton's second law:
</span>

<span>where the term on the left is the resultant of the forces acting on the door, m is the door mass and a its acceleration.
In order to move the door, the acceleration must be different from zero. But this means that the resultant of the forces acting on it must be different from zero: this is possible only if the forces applied by the two persons are unbalanced, i.e. one person exerts more force than the other.</span>
The displacement of the bus is 6.25 miles.
Answer:
The heat added represents an energy change.
Explanation:
Given :
A race car moves along a circular track of radius 100m at a velocity of 25m/s.
To Find :
(a) What is the time taken to complete one lap of the circular track.
(b) What is the time taken for 10 laps.
Solution :
Circumference of circular track,

a) Time taken to complete one lap is :

b) Time taken to complete 10 laps is :

Hence, this is the required solution.