Is it true that every still object has inertia?

The more inert an object is, the most difficult it will be to change its velocity. This applies to changing from 0 m/s to 1 m/s in the same manner as to changing from 1000 m/s to 1001 m/s. That is to accelerate it by 1 m/s.

This is what Newton’s law F = m a means

F is the force you need to apply to a mass m to change its velocity in one second. The larger the mass, the bigger the required force for the same aceleration.

What is wonderful in this relationship is that m, is not inertia to begin with, it’s mass instead. And mass has to do with the quantity of matter, with how many electrons, protons and neutron the object contains. Not with resistance to change in velocity. What Newton found out centuries ago is that the quantity of matter IS inertia. Although you can feel from everyday experience that it’s easier to stop a bicycle than a train, it is amazing that things that seem to have nothing to do with one another actually do.

And it gets even more astounding with gravitation. But that’s for another post.

Every object with a non-zero mass has inertia.

The object doesn’t have to be still – inertia means resistance to change of velocity.

Yes, every still body has inertia