Mass, Weight & Gravitational Field Strength(Edexcel International A Level Physics)

Expertise

Physics

Mass, Weight & Gravitational Field Strength

Mass

• Mass is the measure of the amount of matter in an object
• Consequently, this is the property of an object that resists change in motion
• The greater the mass of a body, the smaller the change produced by an applied force
• The SI unit for mass is the kilogram (kg)

Weight

• Weight is the force a body experiences due to being in a gravitational field, it is given by the equation

W = mg

• Where
• m = mass (kg)
• g = gravitational field strength (N kg−1)

Gravitational Field Strength

• Gravitational field strength is the force per kilogram that acts on an object, it is found using the equation

g =

• Where
• F = weight (N)
• m = mass (kg)
• On the Earth's surface the average gravitational field strength = 9.81 N kg−1

Constant Acceleration in Freefall

• Freefall is used to describe falling objects where the only force is weight
• Drag forces are ignored
• By considering freefall we can see that all objects must fall with exactly the same value for acceleration, regardless of their mass or weight

Get unlimited access

to absolutely everything:

• Unlimited Revision Notes
• Topic Questions
• Past Papers