...describing forces...       Objectives:         Grrr!     • Know that forces can change the shape of an object, or change the way objects move.   • Be able to describe forces using scientific language.   • Be able to measure forces using a Newton meter.     • Know the names of common forces.                 Task 1 - Starter         Hands up!         I know the answer!       Find someone who knows:         1) what units could you use to measure speed?     2) what does accelerating mean?     3) What is a force?     4) Can you think of any examples of forces?         Your teacher will tell you which questions to answer.                 Task 2 - Describing forces                             Images from: commons.wikimedia.org and http://en.wikipedia.org/     Visit the stations in order.  Each of the actions requires you to apply a force.         1) Change the shape of the plasticine.   2) Open the jar, then close it again.   3) Make smaller pieces of card.   4) Lift the mass.   5) Change the shape of the steel rod.     6) Change the length/shape of the rubber.   7) Chop up the cardboard.   8) Put the magnets near each other.   9) Push the block along the sandpaper.   10) Change the length of the spring       What words would you use to describe each force?  Draw a table to record your results.       Prompt sheets / instructions to display by each station are available here.             Task 3 - Reading scales           I'm practising using scales! Image credit: gettyimages.nl       A Newton meter is used to measure forces.         Make sure you can read the scale on your Newton meter correctly.  Practise reading from different scales for each of the readings below:     (a) (b)     (c)   (d)   (e)     Images: BBC Bitesize       What is the scale on your Newton meter?       Teacher note: encourage students to look at the scales on their Newton meters and check they understand them. Discuss why units are called "Newtons", history, Newton trivia (cat flap!) etc.               Task 4 - Measuring forces           Newton meters.     Isaac Newton. Image credit: Wiki Commons.       Use a Newton meter to measure the following forces:       1) Opening a cupboard door.   2) Lifting your stool off the ground.   3) Lifting a 1kg mass.   4) Lifting your pencil case.   5) Pulling up your sleeve.   6) Dragging a stool across the floor.       Draw a table to record your results.       Extension: think of some other actions that involve forces, and use your Newton meter to measure them!             Task 5 - Motion with & without forces             image caption.         A hover puck can show us how an object behaves when there is very little friction.   A hover puck. Low friction kinematics!             Teacher note: Pupils could look at examples of e.g. Voyager 1&2 probes – speed of approx 17km/s, link to lack of air resistance / friction, idea of motion continuing in absence of retarding forces etc.               Extension       The simulation below shows how forces can affect motion.       Teacher notes will be available here, at some point.   Thanks to PhET for this awesome simulation :)     HTML5 technology!  Woop Woop!                 Click this image to load the simulation in full screen mode.   Click to Run                       Homework           Homework makes me clever.           Find out what is meant by:     1) Balanced forces.   2) Unbalanced forces.   3) Friction*.   4) Air resistance.   5) Weight.   6) Thrust.   7) Upthrust.   8) Down force.   9) Normal reaction force.     *Extra challenge: write a paragraph to explain what limiting friction is, what static friction is, and the difference between them.       This task is also available as a word document here. Click the image above to download the document.