This law tells us that an object can have something called a “charge,” and, if it does have a charge, forces can be exerted on the object which are not caused by something in contact with it. We can measure these forces as we measure other forces, for example by measuring the acceleration it causes and the mass of the charged object, or by balancing it with a known force, such as that exerted by a spring with a particular compression and known spring constant.
-- part contents for background part 3
----- text -----
This law tells us that an object can have something called a “charge,” and, if it does have a charge, forces can be exerted on the object which are not caused by something in contact with it. We can measure these forces as we measure other forces, for example by measuring the acceleration it causes and the mass of the charged object, or by balancing it with a known force, such as that exerted by a spring with a particular compression and known spring constant.