Grade 9 natural Science. Contact Forces.

As educators we need to make lessons practical more especially when the content being taught is relatable to learners.

1. Contact forces Presented by MAM Swethane This Photo by Unknown Author is licensed under CC BY-SA-NC

2. Let’s play https://create.kahoot.it/share/natural-sciences/c48ed813-dba3-485b-abd8-46100af65d3b

3. Lesson objectives Define contact forces Identify and provide examples of different types of contact forces, including friction, tension, and compression. 3. Explain the effects of contact forces on the motion and direction of objects in real-world situations.

4. What is a contact force? Contact forces are forces that occur only when two objects are physically touching each other. These forces arise from the interaction at the surface between objects. Types of forces Tension Friction Compression

5. Tension force Tension is a type of contact force that occurs when a rope, cable, or string is pulled tight by forces acting from opposite ends Ropes and Cables : When two people pull on opposite ends of a rope, the rope experiences tension. https://phet.colorado.edu/sims/html/forces-and-motion-basics/latest/forces-and-motion-basics_all.html This Photo by Unknown Author is licensed under CC BY-NC

6. Friction force Friction is a force that opposes motion between two surfaces in contact. Friction slows down a moving subject. Example : Rubbing your hands together produces heat due to friction.

7. Compression force Compression is pushing force that acts to squash or compress an object. This force can also push something into another space. Example : When you sit on a cushion, your weight applies a compression force to it. Toothpaste

8. Reflective questions Can you think of a time when friction was helpful and a time when it was a problem? (3 marks) How could you reduce friction in a moving machine, and why might you want to do that? (3 marks)

9. The end “Knowledge ignites potential”