1. Force & Movement
D. Crowley, 2008

2. Force & Movement
Thursday, November 22, 2018Thursday, November 22, 2018
To be able to explain how the force behind an object affects its movement

3. Acceleration = Force  Mass
If both of these vehicles had exactly the same size engine, which would reach 60 first?
versus
Mass >3000kg
Mass 1200kg
The smaller mini would get to 60 before the large range rover as it has a much smaller mass - if the engine is the same, then the force pushing it forward is the same, so a smaller mass would equal faster acceleration
Acceleration = Force  Mass

4. Acceleration
Draw force arrows needed for each car to accelerate them both at the same rate
versus
As the range rover is almost 3x as heavy as the mini, the force needed to accelerate it at the same rate as the mini needs to be 3x as big
This is why the force arrow for the range rover is so much bigger (and why in real life, it has a much more powerful engine)

5. Force Experiment
How could you investigate how changing the force behind an object will affect how far it moves
Apparatus at your disposal include: -
Rubber bands
Force meters
String
Meter rulers
Stop watches
Ramps
Margarine tubs
Plasticine
Sellotape

6. Force Experiment
Remember, whatever plan you have chosen to follow, you must only change 1 independent variable (the force applied)
Every other variable must be kept constant (i.e. the mass of the margarine tub, the slope it must travel across etc…)
You may have decided to see how different forces affect the distance traveled by a margarine tub containing a given mass of plasticine - you will need to measure how far the tub traveled when different forces (at least 5 different forces) were applied, repeating each experiment at least 3x
Force
10N
15N
20N
Etc…
Distance traveled
Start point
End point

7. Distance traveled by object (cm)
Results
Force
(N)
Distance traveled by object (cm)
Measurement 1
Measurement 2
Measurement 3
Average 10 15 20 25 30

8. Conclusion Analyses your results, and conclude your findings
Evaluate your experiment, and then suggest improvements…
Hopefully you found that as the force increased, the distance traveled by the object increased
As the force increased, whilst frictional forces remained the same (the co-efficient of the frictional force between the ground and tub remained the same)