Euler's First Law and the Conservation of Momentum

[e2m2a]

I know Euler's first law applies to a single body, but can we use it for a system of bodies? Or should we invoke the conservation of momentum to obtain the same result for a system of bodies?

 

[tiny-tim]

Hi e2m2a!

I know Euler's first law applies to a single body, but can we use it for a system of bodies? Or should we invoke the conservation of momentum to obtain the same result for a system of bodies?

hmm … i had to look this up in "[URL , so let's copy it for everyone's benefit …

Euler's first law states that the linear momentum of a body is equal to the product of the mass of the body and the velocity of its center of mass: L = mv_c.o.m. Internal forces, between the particles that make up a body, do not contribute to changing the total momentum of the body. The law is also stated as F = ma_G

(it means we can ignore any rotation, so long as we deal only with the centre of mass )

I don't really understand your question …

surely a system of bodies is a body …

Newton's first two laws are about particles, while Euler's two laws are about collections of particles (called "bodies"), and a collection of collections is still a collection?