A projectile is thrown upward at an angle 60 ° with the horizontal. The speed of the projectile is 20 m / s when its direction of motion is 45 ° with the horizontal. The initial speed of the projectile is \ \ \ \ m / s .

Physics · Motion in Plane

JEE Main 2026 — 22 January, Morning Shift — Question 31

A projectile is thrown upward at an angle $60^{\circ}$ with the horizontal. The speed of the projectile is $20 \mathrm{~m} / \mathrm{s}$ when its direction of motion is $45^{\circ}$ with the horizontal. The initial speed of the projectile is $\_\_\_\_$ $\mathrm{m} / \mathrm{s}$ .

Option A:
$40 \sqrt{2}$
Option B:
40
Option C:
$20 \sqrt{3}$
Option D:
$20 \sqrt{2}$
Correct

Answer: D

Step-by-step solution

$\mathrm{u} \cos 60^{\circ}=\frac{20}{\sqrt{2}}$ $\frac{\mathrm{u}}{2}=\frac{20}{\sqrt{2}}$ $\mathrm{u}=\frac{40}{\sqrt{2}}$ $\mathrm{u}=20 \sqrt{2} \mathrm{~m} / \mathrm{s}$

Answer key and solution verified before publishing.

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Exam: JEE Main 2026
Paper: 22 January, Morning Shift
Subject: Physics
Chapter: Motion in Plane
Topic: Oblique and Horizontal Projectile Motion