Physical sciences June examination P1: Gr 12 Additions/Corrections/Clarification to memorandum

Q3.3
Some learners might use an equation of motion plus Newton's second law of motion to solve this question. That is fine and can be accepted as follows:

Q5.2.2
Additional acceptable explanations are:

• Friction is present.
• A non-conservative force is present.
• Force F is present.
• The non-conservative for F is present.
• An applied force is present.

Q5.2.4

Two alternatives are shown in the memo for the calculation of work done by weight to be used in option 1. Here is a third alternative. It uses cos of 120 degrees being the angle between the vertical weight and the displacement along the inclined plane.

Q7.2 

The two charges differ in magnitude and the density of the field lines should be slightly different for the two charges. Please ignore this and accept a field pattern as in the memo, as well as one where the density of the field lines are different. If the general pattern is correct, award the first mark of the marking criteria and carry on marking the direction and the 90degrees.

Q4.1.1 and Q4.1.2
Keep in mind that the displacement is given by die area between the graph and the time axis, which in this case can be calculated with the help of either a trapezium or the combination of a triangle and rectangle. Q4.1.2 must be marked by taking into consideration what was done in Q4.1.1; i.e. there is positive marking from the graph to the calculation of area.

Here is an example of a graph with incorrect plotting.

All but one of the points are plotted incorrectly, and the mark for the best-fit line is given. Hence, 2/5.

Let us zoom in to the area that represents the displacement.

Here are three examples of the marking based on the above-mentioned.

Q8.3 and further
Typical of some electric circuit questions, there are sometimes various options to solve the questions. Click here to download a pdf file with extra solutions.

Q5.1.4
Another correct option.