## nat5 – work, power and potential energy

We’ve been looking at work and the rate of change of energy.  This handout will help you to revise the key points and introduces gravitational potential energy.

## using Excel’s LINEST function

The period (T) of a simple pendulum can be calculated using

where l is the pendulum length and g is the gravitational field strength.

Using a single value of length and period, we can determine the acceleration due to gravity.  However, it would be better experimental practise to vary the length of the pendulum and plot a graph of against length, determining g from the gradient of the line of best fit.

We’re going to spend the next three periods analysing your simple pendulum data in the library.  The attached pdf will walk you through the steps.  It would be better if you used your own results but I’ve put some sample data on the first page if you’ve forgotten to bring yours.

## higher assignment

I have attached a copy of the Scholar notes for unit 3 of the CfE Higher course.  You will find background physics with appropriate energy band explanations on pages 103-142.

Don’t print this document, it’s huge!

## higher particles and waves revision

Remember that your unit assessment for P&W will take place at the end of this week.  The attached notes might be helpful during your revision.

## particle accelerators

An electric field can be used to accelerate charged particles.

Conservation of energy tells us that

work done by the electric field = change in the particle’s kinetic energy

The speed of the particle can be determined if its charge and the accelerating voltage (potential difference) are known.  The notes attached to the end of this post will show how to perform the calculation.

These short video clips show how to draw electric field lines for point charges and parallel plates, with example calculations for the work done by electric fields and the final speed of charged particles in electric fields.