MASS AND WEIGHT

MASS AND WEIGHT

MATTER

-is a measure of the quantity of matter in an object at rest relative to the observer.

-mass is scalar quantity
-SI unit of mass is kilogram(kg)
-sometimes use gram(g) [1000g=1kg]

Mass is the property of an object that resists change in motion.

The greater the mass = the more difficult it is to speed it up, slow it down, or change its direction

WEIGHT

-The force acting on an object due to gravitational attraction

-weight is a force, so it is a vector quantity
-SI unit of force are Newton(N)

• Objects stay firmly on the ground

• Objects will always fall to the ground

• Satellites are kept in orbit

Because of weight:

​Weight equation triangle:

WHERE:

W = weight (N)
m = mass (kg)
g = gravitational field strength (N/kg)

acceleration of free fall, or acceleration due to gravity.

Also known as:

The force per unit mass acting on an object in a gravitational field.

Defined as:

Gravitational Field Strength

The value of g (gravitational field strength) varies from planet to planet depending on their mass and radius.

its weight will differ depending on the strength of the gravitational field on different planets

An object’s mass always remains the same

MASS vs WEIGHT