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.

Explanation:

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.

#F=m*a#

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

#m*a=0#

By recollecting the definition of acceleration:

#ddotx*m=0#

By integrating both sides with respect time:

#dotx*m=k#

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

#v(t)=k/m#

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

If you integrate once more:

#x(t)=(k/m)t#

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.