JEE Main 2021 · PhysicsNumerical answerNumerical valueEasyCalculation

JEE Main 16 March 2021, Shift 2, Physics Q23

Question 23 of 90 in this shift, Physics question 23 of 30, Section B.

A body of mass 2 kg moves under a force of

(2\hat{i}+3\hat{j}+5\hat{k})

N. It starts from rest and was at the origin initially. After 4 s, its new coordinates are (8, b, 20). The value of b is ________. (Round off to the Nearest Integer)

Official answer

NTA final key.

Chapter: Motion in a Straight Line
Topic: Newton's Laws of Motion
Idea tested: F=ma for Single Body

Same idea in other shifts

Asked 3× in all

4 Apr 2026, Shift 2 · Q28At $t=0$ , a body of mass 100 g starts moving under the influence of a force $\left(5\hat i+10\hat j\right)$ N. After 2 s its position is…EasySingle correct
7 Apr 2025, Shift 2 · Q28An object with mass 500 g moves along $x$ -axis with speed $v=4\sqrt{x}$ m/s. The force acting on the object is :MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.