Weight
This is going to be a short article but make sure you understand Newton's Second Law first.
Weight is actually a force - but we don't use that in a supermarket because people who don't know about physics will definitely find it confusing.
"Hey, I want 20 N of orange!" -that would definitely be confusing.
How do we find the weight of something? Remember Newton's Second Law?
F=ma
Well, gravity on Earth accelerates things at 10m/s^2 (actually it's more like 9.8m/s^2). So whenever you need to know about the weight of something, multiply its mass by 10 and you will get the force in Newtons (N).
So, a woman who weighs 60kg will have a weight of 600 N. Why do all objects fall at the same speed (discounting air resistance?)
Gravity does indeed increase for more mass in an object. The greater the mass, the greater the amount of gravity that acts on it.
However, if you rearrange Newton's second law, you will find out that force is directly proportional to the mass.
F/m=a
As mass increases, the gravity that is applied to it is increased, which balances out to give a constant acceleration for all objects. Another way to view this is to recall mass is also the inertia of an object: so when gravity increases when the mass of an object increases, the inertia also increases, which increases the tendency for an object to resist change.
