Physics Year10 - Mass, Weight and Gravity

What is mass?

Mass is the measure of the amount of matter in an object, typically measured in kilograms (kg). It does not change with location.

What is weight?

Weight is the force exerted on an object due to gravity, measured in newtons (N). It is calculated using the formula: Weight (W) = Mass (m) × Gravitational field strength (g).

What is the gravitational field strength of Earth

On Earth, g is approximately 9.8 N/kg

How does weight change with location?

Weight changes with location because it depends on the local gravitational field strength. For example, weight on the Moon is about 1/6th of that on Earth due to weaker gravity.

What is gravity?

Gravity is a force that attracts two bodies towards each other. On Earth, it causes objects to fall towards the ground.

Calculate the weight of a 10 kg object on Earth

Weight (W) = Mass (m) × Gravitational field strength (g) W=10 kg × 9.8 N/kg = 98 NW

If the gravitational field strength on another planet is 3 N/kg, what is the weight of a 5 kg object there?

Weight (W) = Mass (m) × Gravitational field strength (g) W=5 kg × 3 N/kg = 15 NW

Why does mass remain constant while weight changes?

Mass is a measure of matter and does not change with location. Weight depends on the gravitational field strength, which varies with location, affecting the force experienced by the object.