Friday, 5 February 2016

Temperature difference and cooling of water

Equipment

4 cups of the same size (e.g drinks cups)
lids with small holes in centre
datalogger and 4 temperature probes or 4 thermometers
Kettle
100ml measuring cylinder
stopclock


Method

Heat water in the kettle until near boiling.

Very carefully measure 100ml hot water and put into cup 1.
Use 80ml hot water and 20ml cold for cup 2, 60 / 40 for cup 3 and 40ml hot, 60ml cold for the final cup.

Add the lids and put the temperature probes through the holes. Thermometers could be used if you have no datalogger - in this case note the start temperature of each cup. Start the stopclock.

After 10 minutes pass stop the datalogger or record the temperature from the thermometers again.

Risks.

Spilled water can cause falls if not cleared up swiftly. Hot water can cause scalds, great care should be taken when using hot water, and insulating gloves may need to be used if something is too hot to comfortably hold.

Temperature and viscosity of oils

Equipment

Water bath
Vegetable oil
Boiling tube
Measuring cylinder
Beaker
Polystyrene cup with hole in bottom
Clamp stand
Bung to fit hole mounted on a rod
Stopclock

Method

Heat 50ml of the oil to 50 degrees C in a boiling tube in the waterbath.
When warmed add to the polystyrene cup (with the bung in) held in the clamp and stand.
Remove the bung and start the stopclock.
Stop the stopclock when the oil has run through into the beaker.

Repeat twice more at this temperature, reheating the oil each time and ensuring you start with 50ml each time.

Repeat at 10 degree temperature intervals down to 20 degrees C.

You may wish to use an alternative method of letting the warm oil run from an object if there is other equipment you can use.

Risks

Do not heat above 50 degrees C to prevent the risk of burns. Ensure any spilled oil is cleared up as soon as possible to avoid slips and falls.



Testing improvement of human co-ordination.

Equipment

computer with keyboard with a number pad
10 sheets of paper containing 5 lines of randomly generated strings of 10 digits
stopclock

Method

Have a volunteer sit at the computer and place their non-dominant hand over the numberpad.

Next to them place a piece of paper which has 5 lines of 10 digit numbers on it, covered by another piece of paper.

Uncover the paper and start the stopclock. The volunteer should start to input the digits as fast as they can without going back over errors.

Stop the stopclock when they reach the end of the list.

Record the time.

Repeat another 10 times using a different random string set.

Once all the times have been completed go over each data set entered into the computer and count the number of errors input during each trial.

Risks

This is a safe experiment to carry out, though if it takes the user a long time to complete the task they may need to be given a short screen break.


Co-ordination, reaction times and practice

Equipment

Metre stick


Method

Position a volunteer so they are sat with their non-dominant arm resting in a comfortable position and their hand is held over the edge of the table with the thumb and forefinger facing up.

Hold the metre stick so the end is level with the top of the thumb and forefinger.

Drop the metre stick - the volunteer should catch it as soon as they can. Record the distance showing just above the finger and thumb.

Repeat the experiment at least 10 times, recording the distance each time.


Risks

This is a relatively safe experiment as long as care is taken to ensure that the metre stick falls vertically so that the far end does not approach the volunteers face and eyes.