Module 1 Flashcards
What is required to prove a hypothesis or theory?
Quantitative and Qualitative results, from experiments, supporting the theory or hypothesis
What are the 4 steps to do a successful experiment?
Planning
Implementing
Analysing
Evaluation
What are the 5 steps to Plan an experiment?
Identify all variables that must be controlled.
Select appropriate apparatus and equipment
Select appropriate scientific techniques
Use scientific knowledge to formulate a hypothesis
Evaluate your method to check it’s validity
What is valid data?
Data that answers the original question by making use of appropriate equipment and procedures.
Why is a rheostat commonly used in experiments containing electrical equipment?
It is used to make sure current from power source is of adequate size, so as not to harm or degrade the equipment.
What is a good range of independent variables used and how many repeats should you do?
You should use at least six independent variables add repeat each measurement thrice for each independent variable.
How do you evaluate your methods, during planning, and why should you?
After writing your method you can check and see if you can increase resolution of results by choosing more appropriate equipment, maybe control other factors better. Or maybe better understand and prevent mistakes in the techniques you are using.
You should do this in order to minimise percentage uncertainty and get a more valid and accurate result
For what lengths should you use a vernier calliper and a micrometer screw gauge?
What are their absolute uncertainties?
Use callipers for lengths up-to 12 cm
Use screw gauge for lengths up-to 20mm
Uncertainty is their resolution, so 0.01cm for callipers and 0.01mm for screw gauge
What error may analogue equipment lead to that digital equipment doesn’t?
Parallax error
How can you minimise parallax error?
View the reading at right angles, at 90 degrees
How to accurately present data in tables and graphs?
For tables give headings and write appropriate units alongside them. Leave space for repeats and processing of data.
For Graphs, label the independent variable on the x axis and the dependent on the y axis alongside appropriate units.
Choose an appropriate scale and cover the whole graph with data points.
Make lobf, use appropriate sig figs,
Use sharp pencil to be more accurate
Give title
How can you process and analyse experimental data?
Take means, find gradients of straight lines and tangents of curves, use graph equations, find area under graph, find percentages
What equation is used to manipulate data in graphs?
y=mx+c
How many sig figs or decimal places should you use to represent data in experiments?
You should use the equipment with the highest resolution as a benchmark for sig figs and decimal places, unless stated otherwise.
Do accurate results have higher a percentage difference than percentage uncertainty? Explain.
No, Accurate results have a higher percentage uncertainty than percentage difference. As this would mean that the range of values (in the margin of error) above and below the given answer, according to the given percentage uncertainty, also include the True value.
