0

Guest

Courses New

Can a body have kinetic energy without having momentum? Can a body have momentum without having kinetic energy?

Can a body have kinetic energy without having momentum?
Can a body have momentum without having kinetic energy?

Grade:10

2 Answers

Jitender Pal
askIITians Faculty 365 Points
8 years ago
No a body has kinetic energy without having momentum.
Yes a body has momentum without having kinetic energy.
Momentum of a body (p) is defined as the mass of the body (m) time’s velocity of the body (v).
p = mv …… (1)
Kinetic energy of the body (K) is defined as the,
K = ½ mv2 …… (2)
Where m is the mass of the body and v is the velocity of the body.
The body having zero momentum signifies that, either the body has zero mass or the velocity of body is zero. If either of the mass or velocity is zero, then kinetic energy (K = ½ mv2) will be zero. Therefore it is not possible a body has kinetic energy without having momentum.
The momentum (p) of photon which has zero rest mass of electromagnetic radiation with wavelength λ is,
p = h/λ …… (3)
Where h is the Planck’s constant.
Since the photon has zero rest mass therefore the kinetic energy of the photon is zero, but still the photon has momentum. Therefore a body has a momentum without having kinetic energy.
S Ashok Kumar
13 Points
5 years ago
The total mechanicl energy possessed by a body is sum total of its potential energy and kinetic energy.
i.e. K+U= CONSTANT.
Secondly, Heat energy is the net internal energy possessed by a body due to the vibrational motion of the particles in a solid and random motion in fluids.Any substance possess the atmospheric temperature and hence has both potential energy and kinetic energy.
In both the above cases the translational motion of the body is zero, hence net momentum is zero.
It is better and will be correct to say translational kinetic energy is zero net kinetic energy of the body is not zero.
If net KE becomes zero then no body would have possessed heat and temperature and mechanical energy would have depended on state of body either rest or motion. 

Think You Can Provide A Better Answer ?

Other Related Questions on Mechanics

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More