4 Science 1

From Mr leong:

Physics SPA exam skills 1 and 2:

1. Spend At least 3-5 min reading question.  Take note of important points

2. First task to draw tables and columns.  Save time from transferring
data when they do experiment later.

3. Collect and record all data from experiment.  Process data only
after all measurements are taken

4. All students should have sharp pencil, clear ball point pen,
calculator and 30 cm long transparent ruler to plot graphs.

5. Gradients need not have units unless question specifically ask for
it. Gradient computed to be 3 sf

6. If x starts from zero, y intercept can be read off from graph and
to have same accuracy as y values. Y intercept to have same units as y
values.

7. If x does not start from zero, y intercept to be computed from
y=mx+c. Y intercept to be 3sf in this case and to have same units as y
values.

8. Graph to be at least 50 to 75 percent of graph paper.

9. Size of 1 cross (data point) to be size of 1 small graph paper grid.

10. Line of best fit to draw graph (see workbook for explanation of
line of best fit)

11. No need to indicate title or scale. Need not start x and y axes
from zero unless specified in question.

12. Appropriate scale - Use 2 cm to represent 1,2,5 or 10 units,
10,20,50 or 100 units, 0.1,0.2,0.5 or 1 unit etc.

13. Label x and y axes with units

14. Measured values to follow accuracy of instrument (eg. length
measurements to record to 1 decimal place)

15. Computed values to be 3 sf

16. Identify 2 key sources of errors if asked in question (kinks in wire, overheating)

17. Appropriate conclusion for eg- sin i varies linearly with sin r

18. If mistake is made half way through experiment, carry on with
experiment if there is no time to redo taking note that a considerable
portion of marks are on data processing and graphing.

19.All students should complete all experiments within 20 min so that
time can be spent on data processing, graph plotting and conclusion.

20. Raise hand to alert invigilator to mark intermediate step if
specified in question

21. do 5 or 6 data points unless question specifies so