Which object would have a larger gravitational force acting upon it? (assume the objects are at the same height above the earth.)
a) 5 kg block of wood
b) 100 kg person
c) 412 kg motorcycle
d) 2540 kg elephant

If the objects are all at the same distance from the center
of the Earth, then the gravitational forces between the Earth
and each object only depend on the mass of each object. 
Those forces are least for the 5kg object, and greatest for
the 2,540kg object. 

The gravitational force that attracts each object toward the
center of the Earth is typically referred to as the object's "weight".

It's important to know that there's another force of gravity ... the one
that attracts the Earth toward the object.  And that one is equal to
the object's weight, but pulls in the opposite direction.

Your weight on the Earth is equal to the Earth's weight on you.

This is what a calorimeter is used for simpler ex, to measure calories in food.