A body of mass 2 kg travels according to the law x(t)=pt+qt²+rt³

A Body Of Mass 2 Kg Travels According To The Physics Question

A body of mass 2 kg travels according to the law x(t)=pt+qt²+rt³,where p=3 m/s,q=4 m/s² and r=5 m/s³.The force acting on the body at t=2 s is

Options

(a) 136 N
(b) 134 N
(c) 158 N
(d) 68 N

Correct Answer:

136 N

Explanation:

m = 2 kg, x = pt + qt² + rt³
⇒ dx/dt = p + 2qt + 3rt²
d²x/dt² = 2q + 6rt = acceleration(a)
At t=2s,
a = 2q +12r = 2 x 4 + 12 x 5
= 68 m/s²
F=ma = 2 x 68 = 136 N.

Related Questions:

  1. What is the energy released by fission of 1 g of U²³⁵?
  2. When a mass M is attached to the spring of force constant k,
  3. A disc of moment of inertia (9.8/π²) kg m² is rotating at 600 rpm. If the frequency
  4. Excitation energy of a hydrogen like ion, in its first excitation state, is 40.8 eV.
  5. An amplifier has a voltage gain Av=1000. The voltage gain in dB is

Topics: Laws of Motion (103)
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Your email address will not be published.


*