Question

Assertion :Block a is moving on the horizontal surface towards right under action of force F. all surfaces are smooth. At the instant shown, the force exerted by block A on block B is equal to net force on block B. Reason: From Newton's third law, the force exerted by block A and B is equal in magnitude to force exerted by block B on A.

• 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. Assertion is incorrect and Reason is correct

Answer 1

The correct option is D Assertion is incorrect and Reason is correct

$\text{Net force of block}B=\sqrt{N_1^2+{(m_B\cdot g)}^2}$

$\text{Since it is not equal to}{N}_1\text{, therefore statement}I$

$\text{i.e. Assertion is wrong. The force exerted by block}$

$\text{A on block}B\text{is not equal to net force on block}B\text{.}$

$\text{we know that Newton's third Law states that}$

$\text{for every action, there is an equal and opposite}$

$\text{reaction. So the force exerted by block}A\text{on}B\text{is}$

$\text{equal in magnitude to force exerted by block B}$

$\text{on}A\text{.}$

$\text{Answer: Assertion is incorrect and Reason is correct.}$