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>
Here refrigerator removes 55 kcal heat from freezer
Refrigerator releases 73.5 kcal heat to surrounding
So here we can use energy conservation principle by II Law of thermodynamics
the law says that

here we know that
= heat released to the surrounding
= heat absorbed from freezer
W = work done by the compressor
now using above equation we can write



So here compressor has to do 18.5 k cal work on it
Answer:
add text fully or atleast add book name edition . solution is in picture. chk pictures ignore b part
Explanation:
Work:
1 kilometer = 1000 meters
45 × 60 = 2700
W = F × D
W = 2,000 N × 1,000 m
W = 2,000,000 J
P = W ÷ t
P = 2,000,000 J ÷ 2,700 s
P = 741 watts
Answer:
741 watts of horse power.
Answer:
The tennis ball will have more kinetic energy
Explanation:
It will have more kinetic energy because the tennis ball is more heavier than a wiffle ball. Furthermore, objects that are heavy will have more kinetic energy than objects that are light. Therefore, the tennis ball is the correct answer.