Question

Assertion : A body is moved from $x=2$ to $x=1$, under a force $F=4x$, the work done by the force is negative.
Reason: Force and displacement are in opposite directions.

• A. Both Assertion and Reason are true and the Reason is correct explanation of Assertion
• B. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
• C. Assertion is true but the Reason is false
• D. Assertion is false but the Reason is true

Answer 1

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

$W=\int \overrightarrow{F}.\overrightarrow{ds}={\int }_2^1\left(4x\right)dx=2x^2{|}_2^1=-6\text{J}$
Here, $\overrightarrow{F}$ and $\overrightarrow{ds}$ are in opposite direction w.r.t to each other therefore negative work.