Conclusion:
The digital thermometer was the more accurate instrument, with a more accurate reading to 1 decimal place, rather than the analogue thermometer’s reading of no decimal places (2 significant figures).
Evaluation:
- A parallax error may have taken place; eyes must be directly above the reading of the thermometer.
- Stirring could have generated a little extra heat, which may have altered results.
Measuring Objects using the Metre Rule and Vernier Calliper
Aim:
To find the level of accuracy and the more accurate measuring instrument between the metre rule and the vernier calliper, by measuring the diameter of an object.
Apparatus:
- Vernier calliper
- Metre rule
- Object (cube)
- Pen
- Paper
Method:
- Check for a zero error in the vernier calliper
- If positive or negative zero error present, record the zero error
- Take the cube and place it between the jaws of the vernier callipers
- If zero error was present, subtract the zero error to get the actual value
- Record the diameter of the cube
- Take the cube and measure the diameter using a metre rule
- Record the diameter of the cube
Diagrams:
(with vernier calliper)
(with metre rule)
Results:
Conclusion:
The vernier calliper is a more accurate instrument. The readings are also seen to be more accurate on the vernier calliper, as they are to 2 decimal places, while the readings from the metre rule are to 1 decimal place. I can conclude that the diameter of the vernier calliper is 1.87 cm.
Evaluation:
- A parallax error may have taken place; eyes must be directly above the reading of the vernier calliper and metre rule
- There was an uncertainty on the vernier calliper of ±0.005 cm and on the metre rule of ±0.05 cm
Measuring Mass and Volume Using Lab Equipment
Aim:
To measure the mass and volume of an object using lab equipment. This can be further used to calculate the density.
Apparatus:
- Object (cube)
- Digital Balance
- Measuring Cylinder
- Water
- Pen
- Paper
- Calculator
Method:
- Put the cube on a balance and measure the mass of the object.
- Fill water in a measuring cylinder. Record the initial volume of water.
- Place the cube in the measuring cylinder with water and record the final volume of water.
- Subtract the initial volume from the final volume and record the volume of the cube
-
Calculate, using the mathematical method to measure the volume by using the reading that was derived from the vernier calliper in the previous experiment. (reading3 )
- To calculate the density, use the formula:
Diagrams:
(measuring mass on a digital balance) (measuring volume using measuring cylinder)
Results:
Conclusion:
Using the mass and volume derived, we can then calculate the density. This was calculated to be 3.81g/cm3. The measuring cylinder is not an extremely accurate instrument, and calculating the volume using the mathematical method seemed to be very accurate.
Evaluation:
- A parallax error may have occurred when recording the readings from the measuring cylinder.
-
There was an uncertainty on the measuring cylinder of ±0.1cm3 and on the digital balance of ±0.001g, which may have resulted in a slight error in the results.