Gravity, normal forces and applied forces booklet
Gravity, normal forces and applied forces booklet
- Unit 1: Life cycles of flowering plants
- Unit 2: Sound
- Unit 3: States and properties of matter
- Unit 4: The digestive system
- Unit 5: Forces and magnetism
- Unit 6: Seasons and adaptations of plants and animals
🌟 This Topic is About...
- 🌍 I will learn about different forces like gravity, normal, and applied forces.
- 💪 I will find out how to draw force diagrams that show the names and directions of forces acting on an object.
Get ready to explore how forces make things move! ⚙️🧲
🌍 Gravity and Normal Forces
Gravity is very important in our everyday lives. Without gravity, we would float away from the Earth! If you kicked a ball, it would never come back down. Gravity works on both still and moving objects — it pulls everything towards the Earth.
Gravity is a type of force that attracts all objects towards the centre of the Earth. This invisible pull keeps us — and everything else — safely on the ground.
💪 Understanding Normal Force
A normal force is a support force. It happens when an object is in contact with another surface — like a book resting on a table. The table pushes up on the book to balance the pull of gravity, keeping the book still.
The book pushes down because of gravity, while the table pushes up with an equal force. These two forces are balanced, so the book doesn’t move. We call this upward push the normal force. Even though we can’t see these forces, we can show them on a force diagram.
💡 Understanding Force Diagrams
We can show the direction of forces using a force diagram. Each force is represented by an arrow. When two forces are equal, their arrows are the same size but point in opposite directions.
Forces always act in pairs. In the diagram, the book exerts a downward force on the table — this is the pull of gravity. The arrow for gravity points down. The table pushes back up on the book with an equal force, called the normal force. The arrow for this force points upward. Since these two forces are equal and opposite, the book stays at rest.
🔍 Think like a scientist — Using force diagrams
🤔 Question: How can we show the direction, size, and type of forces acting on an object using a force diagram?
🧰 You will need: A pencil ✏️, ruler 📏, and your observation skills 👀.
📝 Investigation Steps:
- How do we show forces on a force diagram?
- How do we show the direction of the force?
- How do we show the size of the force?
- Look at the force diagram of a person sitting on a chair. Which forces do the arrows show?
- When you stand still, why don’t you sink into the ground? Draw a force diagram to explain your answer. Label gravity and normal force.
🌟 Tap to See Answers
- 1–3: We show forces using arrows. The direction of the arrow shows the direction of the force, and the size of the arrow shows the strength of the force. 🏹
- 4: The arrows show gravity pulling down and the normal force pushing up. ⚖️
- 5: You don’t sink because the ground pushes up with an equal force — the normal force — that balances gravity. 🌍⬆️
Well done, young scientist! You’ve learned how to show invisible forces on a diagram. 💪✨