Here is your next homework exercise. You must hand this in **no later than Thursday 29th January** if you want to have it corrected and receive feedback before the Physics prelim on Monday 2nd February. The questions are on AC electricity and charging/discharging of capacitors.

# podcast

podcasts go in this category for the feed to iTunes

## charging & discharging capacitors

We looked at factors affecting the shape of the charging & discharging curves of capacitors today. Here is a video I found on youtube that covers some of the areas we discussed. Ignore the maths bit at the end, we won’t need that. Notice how the man in the film uses a lightbulb as a way of showing when the current is large or small, clever, eh?

## Higher HW for Friday 16 January

Your HW sheet with questions on EMF and the Wheatstone Bridge is attached. Please hand it in no later than the above date.

## deriving the equations of motion

I’ve been looking through the results of the traffic light survey we did at the end of unit 1 of the higher course. The learning outcome that most people were unhappy about was the derivation of the equations of motion.

I put together a handout that outlines where the 3 equations come from, starting with a simple velocity-time graph. Let me know if you think your understanding of this outcome would benefit from the video treatment I have used in your homework solutions.

## equations of motion – projectile motion

How to separate out the horizontal and vertical motion of a projectile and apply the equations of motion.

## equations of motion – combining up & down vertical motion

This is an example showing the importance of adopting a sign convention at the start of your problem.

## equations of motion – final velocity

An example illustrating how to determine the final velocity of an object when initial velocity, acceleration and distance are known.

## equations of motion – initial velocity

This example shows how to find the initial vertical velocity of an object if its maximum height (apex) is known.

## equations of motion example – finding “g”

In this problem, experimental data is used to obtain a value for “g”, acceleration due to gravity.

## Higher HW – gas laws and electric fields

Here is your HW covering the end of unit 1 and the start of unit 2. This exercise is slightly longer (7 questions) so that you won’t have to do any HW over the Christmas holidays. Make sure you hand in your answers no later than Monday 15th December.