POE Predict-Observe-Explain : ask students to predict what will happen in the following situations and then get them to observe each event before attempting to explain their observations:.
After exploratory discussion, invite students to write about what a world would look like without friction. How would it be different to our existing world? What tasks could still be done and what tasks would need to be done differently?
Teaching procedure -Two Minute Bursts. This procedure has been used near the end of a unit to encourage students to make links to everyday experiences and otherwise think about what they have learnt in other ways. The teacher puts one at a time a series of provocative or 'off beat' assertions relevant to the content on the board.
The students have two minutes deliberately chosen as a short time to promote intense thinking to jot down as dot points relevant thoughts and reactions.
The teacher calls for points that do and do not agree with or support the statement and then puts up the next assertion. Our website uses a free tool to translate into other languages. You could not walk without the friction between your shoes and the ground. As you try to step forward, you push your foot backward. Friction holds your shoe to the ground, allowing you to walk. Consider how difficult it is to walk on slippery ice, where there is little friction. Writing with a pencil requires friction.
You could not hold a pencil in your hand without friction. For instance, while two rough surfaces such as sandpaper rubbing against each other sometimes have more friction, very smoothly polished materials such as plates of glass that have been carefully cleaned of all surface particles may actually stick to each other very strongly.
There are two main types of friction, static friction and kinetic friction. Static friction operates between two surfaces that aren't moving relative to each other, while kinetic friction acts between objects in motion. In liquids, friction is the resistance between moving layers of a fluid, which is also known as viscosity. In general, more viscous fluids are thicker, so honey has more fluid friction than water.
The atoms inside a solid material can experience friction as well. For instance, if a solid block of metal gets compressed, all the atoms inside the material move, creating internal friction. Teflon on non-stick cookware reduces friction between the food and the pan, causing the food to slide.
Competitive swimmers wear specially designed racing suits to reduce the friction between themselves and the water so that they can swim faster. Silicone aerosols, oils, grease and ball bearings are all used to reduce friction. Air resistance force is the force of air pushing against a moving object. Air resistance also called drag is a type of frictional force.
Like all frictional forces, the force of air resistance always opposes the motion of an object. Usually, the air resistance force is not very strong. When you walk, for example, you are affected by air resistance force, but it does not really slow you down. If you start running, the air resistance force will become more noticeable. Rosin - a hard resin ranging in colour from amber to dark brown.
Used for varnishes and other products, to increase friction, e. Static electricity - a stationary electric charge that builds up on an insulated object such as a thunder cloud Streamlined - to design or build something with a smooth shape so that it moves with minimum resistance through air or water Surface area - a solid flat area.
Need help? How to videos Why join? Friction and resistance. What are friction and resistance? Although wheels are great for rolling and reducing friction, they couldn't work without friction. It would be really tough just to stand up without friction. Friction can generate static electricity.
The harder two surfaces are pressed together, the more force it takes to overcome the friction and get them to slide. Fluid friction is used a lot in water parks so we can slide smoothly and fast down giant slides. Racing cyclists crouch down low on their bikes to reduce the air resistance on them.
This helps them to cycle faster. They also wear streamlined helmets. These have special, smooth shapes that allow the air to flow over the cyclist more easily. Ice causes very little friction , which is why it is easy to slip over on an icy day.
However this is a good thing for ice skating and sledging.
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