Question

Assertion :A man in a closed cabin falling freely does not experience gravity. Reason: Inertial and gravitational mass have equivalence.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

By Newton's third law forces occur in pair of action and reaction but in case of free fall there is no reaction or normal force

$mg-N=ma$

$mg-N=mg$

$N=0$

hence the man feels no gravity.

Now,

Gravitational mass:

$F=\frac{G{m}_1{m}_2}{r^2}$

where $m_1$ and $m_2$ are the masses of two objects.

Inertial mass:

$m=\frac{F}{a}$

no difference has been found between gravitational and inertial mass. Many experiments have been performed to check the values and the experiments always agree to within the margin of error for the experiment. Einstein used the fact that gravitational and inertial mass were equal to begin his Theory of General Relativity in which he postulated that gravitational mass was the same as inertial mass