Laws of Motion

JEE Main level, single correct, medium

35 of 210

Question 35 of 210

Two billiard balls of equal mass 30g30g strike a rigid wall with same speed of 108kmph108kmph (as shown) but at different angles. If the balls get reflected with the same speed, then the ratio of the magnitude of impulses imparted to ball aa and ball bb by the wall along XX direction is:

Show answer and solution

Answer: (B) 2:1\sqrt{2}:1

Impulse == change in momentum
Ball (a) ∣Δp⃗∣=2mu=J1|\vec{\Delta p}|=2mu={J}_{1}
Ball (b) ∣Δp⃗∣=2mucos⁡45∘=J2|\vec{\Delta p}|=2mu\cos 45^{\circ}={J}_{2}
J1J2=1cos⁡45∘=2\dfrac{{J}_{1}}{{J}_{2}}=\dfrac{1}{\cos 45^{\circ}}=\sqrt{2}

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: Laws of motion, friction and pulleys simulationDrag the sliders and watch the numbers in this question change.

More Physics practice

JEE Main Physics practice question on Laws of Motion (Newton's laws of motion), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.