when linear momentum is zero, then kinetic energy is not zero.Why?

Asked by svmic.dbr | 7th Oct, 2014, 06:54: PM

Expert Answer:

When we consider the momentum and kinetic energy for a single particle:

begin mathsize 14px style We space know space that space straight p equals space mv space and space Kinetic space Energy equals space fraction numerator straight p squared over denominator 2 straight m end fraction When space straight p space equals 0 space comma space straight K. straight E space equals 0 space end style

But when we consider the motion a body made up of number of particles, the kinetic energy won’t be zero even when the linear momentum is zero.Because there will be an internal energy in the body due to the thermal agitation of the particles of the body, while the vector sum of the momenta of the moving particles may be zero.i.e. individual atoms can have kinetic energy (thermal motion) even though the whole object has zero momentum

Answered by Jyothi Nair | 8th Oct, 2014, 10:42: AM