This key facts covers Resultant Force within Forces & Their Effects for GCSE Physics. Revise Forces & Their Effects in Forces for GCSE Physics with 28 exam-style questions and 11 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 5 of 13 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
🎯 Resultant Force
Definition: The single force that has the same effect as all the individual forces acting on an object combined.
For forces in a straight line:
- Same direction: ADD them
- Opposite directions: SUBTRACT (bigger − smaller)
- Direction is that of the larger force
Examples:
- 500 N forward + 200 N forward = 700 N forward
- 500 N forward + 300 N backward = 200 N forward
- 500 N up + 500 N down = 0 N (balanced)
Quick Check: A 5 kg object is on Earth where g = 10 N/kg. What is its weight?
Weight = m × g = 5 × 10 = 50 N. Remember: mass is 5 kg everywhere, but weight depends on the local gravitational field strength.
Practice questions for Forces & Their Effects
What is a force?
Explain what is meant by the resultant force on an object.