Question

Assertion When $\theta=45^{\circ}$ or $135^{\circ}$, the value of $R$ remains the same, only the sign changes.
Reason $R=\frac{u^{2} \sin 2 \theta}{g}$

• A. Both assertion and reason are true and reason is the 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 reason is false.
• D. Both assertion and reason are false.

Answer 1

Answer: (A)

Horizontal range $=\frac{u^{2} \sin 2 \theta}{g}$
When $\theta=45^{\circ}$, maximum horizontal range
$R_{\max }=\frac{u^{2}}{g} \sin 90^{\circ}=\frac{u^{2}}{g}$
When $\theta=135$, maximum horizontal range
$R=\frac{u^{2}}{g} \sin 270=\frac{-u^{2}}{g}$
Negative sign implies opposite direction.