Unit 4E: Friction Friction T Unit 4E: Friction

Useful Words Friction A force acting between two surfaces Unit 4E: Vocabulary Useful Words Friction A force acting between two surfaces Air resistance Friction caused by a body moving through air Water resistance Friction caused by a body moving through water Forcemeter A piece of equipment for measuring force Newtons The units in which force is measured Surface area The face of a body V Unit 4E: Vocabulary-

Unit 4E: Forcemeters : L.O. 1,2 : NC. 4.2e 3 Newtons 7 Newtons 5 Newtons 8.5 Newtons A Unit 4E: Forcemeters : L.O. 1,2 : NC. 4.2e

Unit 4E: Using Forcemeters Try hanging different objects from around the classroom on the forcemeter. Write down the readings you get! Object Forcemeter reading in Newtons A Unit 4E: Forcemeters : L.O. 1,2 : NC. 4.2e

Unit 4E: Forces against movement This picture shows the same box being pushed on different surfaces. D Unit 4E: Forces against movement: L.O. 3 : NC. 4.2d

Unit 4E: Forces against movement D Unit 4E: Forces against movement: L.O. 3 : NC. 4.2d

I Investigation: Which surface do objects slide on most easily? Unit 4E: Investigation Investigation: Which surface do objects slide on most easily? Which of these surfaces will a weighted box slide across most easily? A) Vinyl B) Wood C) Carpet When you have chosen, explain why you think this surface will be the easiest to slide across I Unit 4E: Investigation : L.O. 4, 5, 6, 7, 8 : NC. 1.1b; 1.2d, e, f, g, h, j

Unit 4E: Investigation (cont.) Investigation: How are you going to test this? “What variable are you testing? (the thing that changes)” “What variable will you change?” “What variables will remain the same to make it a fair test?” “What will you measure?” Record the results as a bar chart, ask for help if you’re unsure. I Unit 4E: Investigation : L.O. 4, 5, 6, 7, 8 : NC. 1.1b; 1.2d, e, f, g, h, j

Unit 4E: What is this force? D Unit 4E: Forces against movement: L.O. 3 : NC. 4.2d

Unit 4E: High and Low Friction Is it best for each of the following to have high or low friction? Situation High Friction Low friction Tyres on a car Playground slide Goalkeeper’s gloves Shoe laces A drawer Ice skates Climbing rope D Unit 4E: High and Low Friction: L.O. 3 : NC. 4.2d

Unit 4E: Water Resistance Which shape do you think will travel through the water the quickest? Why do you think this one will be the quickest? Test different shapes to see how quickly they move through the liquid. A Unit 4E: Water Resistance: L.O. 11, 12 : NC. 4.2 c, d

Unit 4E: Water Resistance movement water D Unit 4E: Water Resistance: L.O. 13 : NC. 4.2 c, d

Unit 4E: Air Resistance: L.O. 13 : NC. 4.2 c, d movement air resistance D Unit 4E: Air Resistance: L.O. 13 : NC. 4.2 c, d

Air resistance- force on an object Unit 4E: Summary brakes ice skates Rough: high friction Smooth: low friction tyres slide goalkeeper’s gloves drawers Force between moving solid surfaces Friction: a force Air resistance- force on an object moving through air Water resistance- force on an object moving through water Big area: High resistance Non streamlined: High resistance Streamlined: Low resistance Small area: Low resistance dart streamlined car sail (boat) parachute person walking through water submarine fish boat S