Additional Physics – Forces L/O :- To understand the effect a force can have on an object “Feel the force” Exam Date -

22/10/2015 Watch this clip – What are the forces acting on the car? Are the forces balanced when the car a) starts off? b) is at a steady speed c) slows down? Insert car lap clip ????

22/10/2015 What do we know about the forces on these cars and what will they do to the movement of the car?

I came up with a few rules to explain how forces will affect movement Sir Isaac Newton Unbalanced forces will cause a change in motion (i.e. speed up / slow down) Balanced forces will NOT cause a change in motion (i.e. stopped or steady speed For every action there is an equal and opposite reaction AND...

22/10/2015 What do the forces tell us about the movement of these animals? 1) This animal is either ________ or moving with _____ ______ because... 4) This animal is ___________ because... 2) This animal is getting ________ because... 3) This animal is getting _______ because...

22/10/ N100N700N600N 700N 200N 800N 100N 50N The overall force in one direction is called the result force What would the resultant force be in these examples? So what can you say about resultant force and movement?

TASK You are going to document the journey of a wind up toy across the room Someone will need to measure the room and place someone with a stop watch every 1m. We will then start the toy and we will all start our stopwatches at the same time. Each timer will press stop as the toy passes them Distance (m)Time (s) What sources of error can you see in this method?

Now draw a graph to show the journey. Think about What type of graph do you need and why? Which why round will you have your axis? What should you include on your graph Remember, this graph is showing a journey not a pattern so it will have one important difference to most graphs you draw. What do you think this may be?

22/10/2015 Distance-time graphs Distance (metres) Time/s Shallow diagonal line = Slow speed Horizontal line = Stopped Steep diagonal line = Faster speed How could you work out the speed from this graph? Speed (m/s) = Distance (m) Time (s) D T S x

22/10/ )What is the speed during the first 20 seconds? 2)How far is the object from the start after 60 seconds? 3)What is the speed during the last 40 seconds? 4)When was the object travelling the fastest? Distance (metres) Time/s

Now work out the speeds from your own graph Higher Tier The speed can also be worked out from the gradient of the line Gradient = vertical Horizontal

‘I left school to walk to the shop – I walked slowly for 10 minutes, covering a distance of 1500m. At the shop I stopped to talk on the phone for 5 minutes. Having realised I was about to miss my bus I ran for 2 minutes to the bus-stop which was 1800m away…’ 1) Complete a graph of the following journey (plot the time (seconds) on the x-axis and the distance (meters) on the y-axis) 2) Work out the speed during the different sections (walking; stationary and running) Key information: - – 10 minute (600 seconds) walk covering 1500m – 5 minute (300 seconds) stationary covering 0m – 2 minute (120 seconds) run covering 1800m – *Total time = 17 minutes (1020 seconds); total distance = 3300m

Steady speed (2.5 m/sec) Steady speed (stationary) (0 m/sec) Steady speed (15 m/sec) 1500 ÷ ÷ ÷ 120

So how much would your graph be worth in coursework? X Axis – a suitable scale has been chosen and labelled with UNITS (the scale should occupy at least 1/3 of each axis) Y Axis – a suitable scale has been chosen and labelled with UNITS (the scale should occupy at least 1/3 of each axis) Points or bars plotted correctly to within 1mm (allow 1 error in 5 points) Suitable line drawn on the graph or bars correctly labelled on bar chart. If no line possible this should be stated on the graph What is your target for next time you do a graph?

What have you learnt? Do you know what balanced forces will do to the motion of an object? Do you know what unbalanced forces will do to the motion of an object? Do you know how to work out speed? Do you know which way the axes on a distance-time graph show? Do you know what a flat line on a distance-time graph shows? Do you know what a steep line on a distance-time graph shows