Question #b331e

1 Answer
Oct 3, 2015

The three of laws of Newton are independent, that is why they are called three laws, not just one. But you can use F=ma to "guess" the first law.


The first law of Newton states that a body either tends to stay in rest or in a straight line with constant speed; that is, no force is present herein.

If you are familiar with Calculus, you can play a little bit.


If we have no force present, which is the case for the first law:


By recollecting the definition of acceleration:


By integrating both sides with respect time:


k is an arbitrary constant. Recollect that #v(t)=dotx(t)#


Which means that the speed is constant, you are either is in rest or constant speed.

If you integrate once more:


Which means that the higher is the mass, the more difficult it is to move, the inertia, which is the first law of Newton in other terms.