Question

When a fruit falls from a tree,
A. only the earth attracts the fruit
B. both the earth and the fruit attract each other
C. only the fruit attracts the earth
D. they repel each other

Answer 1

Hint: Fruit falls from a tree due to gravitational pull. Now, according to Newton’s third law of dynamics, every force has an equal and opposite reaction. Therefore, the fruit will also attract the earth with a force equal in magnitude but opposite in direction.

Formula used: Newton’s second and third laws of dynamics.
$F = ma$ (m $=$ mass, a $=$ acceleration)
${\vec F_{AB}} = - {\vec F_{BA}}$

Complete answer:
Fruit falls from a tree due to gravitational pull. Now, according to Newton’s third law of dynamics, every force has an equal and opposite reaction.
i.e. ${\vec F_{AB}} = - {\vec F_{BA}}$
Therefore, if the earth attracts the apple, the apple would also attract the earth with the same intensity of force.

Hence, the correct answer is option B.

Note: However, the displacement of the two bodies will be inversely proportional to their respective masses, since from the second law of dynamics we know $F = ma$
Therefore, as fruits have lesser masses as compared to that of the earth, they will fall down from trees while the displacement of the earth towards the fruit will be insignificant.
Keep in mind that the fruit will attract the earth with a force equal in magnitude but opposite in direction, since according to the third law of dynamics every force has an equal and opposite reaction.