Motion and Forces

Outcomes 5.6.2a) describe qualitatively the relationship between force, mass and acceleration 5.6.2b) explain qualitatively the relationship between distance, speed and time 5.6.2c) relate qualitatively acceleration to a change in speed and/or direction as a result of a net force 5.6.2d) analyse qualitatively common situations involving motion in terms of Newton’s Laws. 5.6.6a) distinguish between the terms ‘mass’ and weight

Skills 5.13.1e) identify the appropriate units to be used in collecting data 5.13.1g) formulate a means of recording the data to be gathered or the information to be collected 5.13.2 a) identify variables that need to be held constant if reliable first-hand data is to be collected 5.13.2 b) specify the dependent and independent variables when planning controlled experiments 5.13.2 c) describe a logical procedure for undertaking a simple or controlled experiment 5.14 a) follow the planned procedure when performing an investigation 5.14 d) record data using the appropriate units 5.15 a) make and record observations and measurements accurately over a number of trials 5.15 b) use independently technologies such as ticker timers 5.18 d) use symbols to express relationships, including mathematical ones, and appropriate units for physical quantities 5.18 f) graphs and tables to show relationships and present information clearly and/or succinctly 5.18 g) select and draw the appropriate type of graph to convey information and relationships clearly and accurately

Spelling List Motion Velocity Distance Speed Direction Gravitational Inertia resistance Mass Weight Displacement Qualitative Gravity Calculating Relationship

Describing Motion The first thing you need to do in this topic is learn the Scientific meanings for some terms that you may use everyday in a different way. In your SC you will have to use them correctly. You also need to learn the correct units used when writing each component. Use these ALL the time!! Distance is measured in metres (m) for calculations. It is how far an object has travelled. Time is measured seconds (s). It is how long an object has taken to travel. Displacement is how far you end up from where you started, and in which direction (up, left, north, towards the window). It is distance with direction. You travel a considerable distance each day, but your overall displacement is likely to be zero. You will end up in the same bed that you crawled out of this morning.

Speed is a measure of how far you can go in a certain time period Speed is a measure of how far you can go in a certain time period. (Speed is the rate at which you cover a distance.) We can calculate speed by using the following equation: SPEED = DISTANCE TIME The units used are metres per second (m/s or m s–1 ) You will need to be able to calculate speed, distance or time using this equation. Here is an easy way to change the subject of an equation.

Easy Equation Use Distance Speed Time Cover up the factor you need to find and you will see how to calculate it. Distance Eg. If you need to find distance…cover distance and… you will see that it is found by Speed x time Speed Time

Practice Time Now use the equation triangle to calculate these. 1. Calculate speed if the time taken was 10 seconds and the distance travelled was 30metres.(Don’t forget to show your working out and units) 2. If a runner ran 30 seconds at a speed of 5 m/s, how much distance was covered? 3. A toy car raced along a 10m track at a speed of 2 km/hour. How long did it take for the car to get to the end of the track. (CAREFUL! What units are used to measure distance?)

Velocity Velocity is speed in a given direction. Wind movement is an example of velocity eg 20km/hour easterly You can calculate velocity using the same equation as speed. NOTE – It really is displacement used and not distance. This only matters when you are expressing the answer in Year 10.

Did You Know???? The speed limit for cars in France was 13 km/h in 1893. Originally all cars in Great Britain had to have a man walking in front of them with a red flag to alert horseriders! In 1896 the speed limit was raised to 20 km/h, and in 1904 to 33 km/h. The first Australian speeding ticket was given to a Tasmanian,George Innes, who was recklessly driving a car through Sydney at 13 km/h. THINK!! What challenges did scientists face as technology allowed cars to travel faster? List your ideas.