Investigating Levers AQA Triple Science P3 – Stretch Project!
Introduction
This is a great “technical practical” that you can use to investigate how a lever works, but in
a fun practical way. It requires some tricky kit, so you might need to go do to the local tyre shop to see if they will let you have a go!
Equipment…
- Force Sensor (range 0.1N to 500N) (link – for suggested type of sensor)
- Alloy rim with tyre
- Metal Lever (0.6m) (link – suggested type)
- 30cm ruler
- Black marker pen
- Multimeter – set to ohms
Safety: to avoid cuts or crushing injury wear gloves and heavy duty shoes, in case your hands slip on the lever as you apply forces.
Method
- Calibrate a resistance based force sensor using weights and a multi-meter set to ohms. Create a graph so you can convert resistance to a specific force.
- Put car wheel on the floor on its side.
- Glue a force sensor to the tyre lever on the top of the “load side”
- Put markings for distance on a tyre lever every 0.05m from the pivot point and pivot point itself.
- Hold the lever with one hand at the nearest point to the pivot, apply enough force to pull the rubber over the rim.
- Record the distance, reading on the multimeter in a table then use the graph to convert to a load force which should also be recorded.
- Replace the rubber and repeat steps 5 and 6 but 0.05m further away. Record all the results in a table.
- Graph the load force v distance from pivot and look for a pattern.
- Repeat with a 2nd wheel and compare graphs.
Control Variables
- During the experiment you must control certain factors. You hand must not slip or move from the distance to the pivot
- Force sensor must not change angle against the rim or tyre or the results will vary for the resistance
- Pivot point must stay fixed
- Temperature may have an effect on the force sensor so all results must be collected on the same day and in the same place.
