Kinematics

JEE Main level, single correct, medium

280 of 308

Question 280 of 308

A projectile can have the same range RR for two angles of projection. If T1T_1 and T2T_2 be the time of flights in the two cases, then the product of the two time of flights is directly proportional to

Show answer and solution

Answer: (C) R\mathrm{R}

Range is same for complimentary angles. T1=2usin⁡θg\mathrm{T}_1=\frac{2 \mathrm{u} \sin \theta}{\mathrm{g}} and T2=2usin⁡(90−θ)g\mathrm{T}_2=\frac{2 \mathrm{u} \sin (90-\theta)}{\mathrm{g}} and R=u2sin⁡2θgR=\frac{u^2 \sin 2 \theta}{\mathrm{g}}
∴T1 T2=2usin⁡θg×2ucos⁡θg=2Rg. \therefore \mathrm{T}_1 \mathrm{~T}_2=\frac{2 \mathrm{u} \sin \theta}{\mathrm{g}} \times \frac{2 \mathrm{u} \cos \theta}{\mathrm{g}}=\frac{2 \mathrm{R}}{\mathrm{g}} \text {. }

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.
See it move: Projectile motion simulationDrag the sliders and watch the numbers in this question change.Revise Kinematics & Projectile Motion firstFormula sheet, solved examples and the traps students fall into.

More Physics practice

JEE Main Physics practice question on Kinematics (Projectile motion), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.