Force and pressure
Contact and non-contact forces, mass and weight, gravitational fields, density and pressure.
Learning goals
- Distinguish contact forces from non-contact forces
- State that mass measures the amount of matter in a body
- Describe a gravitational field as a region where a mass experiences gravitational force
- Define gravitational field strength as gravitational force per unit mass
- Apply weight = mass × gravitational field strength
- Distinguish mass from weight
- Apply density = mass ÷ volume
- Define pressure as force per unit area
- Apply pressure = force ÷ area
G3 Science (Physics) · Topic 3
Begin with the complete topic lesson. Then try a short check, use the feedback to review one idea and come back later for another attempt.
Before you begin
Build the idea in order
- Forces
- Mass, weight and fields
- Density
- Pressure
Lessons
Force and pressure
Contact and non-contact forces, mass and weight, gravitational fields, density and pressure.
Check your understanding
Force and pressure topic check
Check the required topic capabilities and get focused practice for ideas that need another look.
G3 Science Structured Practice — Measurement, Force and Pressure
Marked practice for G3 Science measurement and pressure: unit and area conversions, reading scales, choosing instruments, density and contact pressure.
What to remember
- Contact forces require touching; gravitational, magnetic and electrostatic forces act at a distance.
- Mass is measured in kilograms; weight is a force and W = mg.
- Gravitational field strength is force per unit mass, measured in N/kg.
- Density is mass divided by volume; convert quantities to compatible units before calculating.
- Pressure is force divided by area, so the same force produces greater pressure over a smaller area.
Topic and syllabus information
Force and pressure is Topic 3 in K326 / K327 Physics component · 2027.
The lesson and questions stay at the depth required for this course.
Reviewed 9 Aug 2026
Continue with the next resource in this course.
Course and syllabus information
- Course
- SEC G3 Combined Science Physics component
- Edition
- SEC G3 Combined Science Physics component 2027