What is the measure of the force of gravity on an object?

Answer 1

The measurement of the force of gravity acting on an object is weight. The weight of an object (or the weight of an amount of matter) is the measure of the intensity of the force imposed on this object by local gravity.

A measure of the force of gravity would be the product of mass and the

acceleration. The unit of which gravity is measured is called a Newton, one

newton is about the same measure of force as 3.6 ounces.

Weight

Force is the product of mass (scalar) and acceleration (vector): F = ma. Weight

is a special case of that formula, where you substitute the acceleration of

gravity, g, for a. We can therefore write: W = mg.1

For example, if an object has a mass of 10 slugs2, its weight near the surface of

the Earth is 10 x 32.2 (ft/s2) = 322 pounds (pound-force). If an object has a

mass of 10 kilograms, its weight near the surface of the Earth is 10 x 9.8 (m/s2)

= 98 newtons.

You can measure the force of gravity on an object (i.e., its weight) by putting it

on a scale.

Strictly speaking, the Force due to gravity is always measured between two

objects. The acceleration due to gravity ('a') in the above discussion is a special

case of acceleration that occurs due to the force of gravity present at sea level

on Planet Earth.

We can calculate the gravitational force between any two objects using the

following formula

Fg = G (m1 x m2) / r2

Where:

Fg - is the force due to gravity

G - is the universal gravitational constant

m1 - is the mass of the first object

m2 - is the mass of the second object

r - is the distance between the centres of the two objects

When using the SI units, G is 6.67 x 10-11 N m2 / Kg2

1. Hypercritically we should say to substitute -g for a in the equation, because many physicists think of g as a negative quantity, inasmuch as it's a vector in the downwards direction; that is, it is directed toward the center of the Earth. When dealing with weight and the acceleration due to gravity, one must be careful to be consistent in assigning the signs.

2. Whenever possible, use the slug, not the pound-mass, in making calculations of mass. The whole pound-mass/pound-force thing is infuriatingly confusing for students. (And some teachers, too.)

Answer: mass x 9.8 meters/second/second. mass x acceleration is force and acceleration due to gravity is 9.8m/s/s. If you take a cannonball weighing 20lb and one 30lb, they would fall at the same rate but one has more force or energy in its motion.

Additionally, the force of gravity at earth's surface measured upon the scale must be added with that force of gravity which is effected upon us by the spin of the earth. (Honk! That's not a force of gravity. In fact, the spin causes no force at all.) For example, the force of gravity at the equator due to our velocity comes by law of Newton to 18.24 lb for a person of 165 scale weight. This then must be added to a total of 183.24 lb as the factual total of his or her gravitational pull.

Answer 2

Acceleration and velocity