A force F=ai+3j+6k is acting at a point r=2i-6j-12k. The value of α for

A Force Fai3j6k Is Acting At A Point R2i6j12k The Physics Question

A force F=ai+3j+6k is acting at a point r=2i-6j-12k. The value of α for which angular momentum about origin is conserved is

Options

(a) 2
(b) zero
(c) 1
(d) -1

Correct Answer:

-1

Explanation:

From Newton’s second law for rotational motion,
τ = dL / dt, if L = constant then τ = 0
So, τ = r × F = 0
(2î – 6ĵ – 12k̂) × (αî + 3ĵ + 6k̂) = 0
Solving we get α = -1.

Related Questions:

  1. A force of 5 N is acting on an object. Displacement of object is 10 m and the work done
  2. Steam at 100⁰C is passed into 20 g of water at 10°C. When water acquires a temperature
  3. If the velocity of charged particle has both perpendicular and parallel components
  4. A simple pendulum has a time period T₁ when on the earth’s surface and T₂ When taken
  5. Infinite number of masses, each 1 kg, are placed along the x-axis

Topics: Motion of system of Particles and Rigid Body (73)
Subject: Physics (2479)

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*