I’ve marked your HW jotters and will hand them back during tomorrow’s lesson.
I’ll go over the main issues in class but many of you need to review the way you attempt tension questions; use a free body diagram and only use F=ma when you know the resultant force. These two videos should help.
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.
At the end of Our Dynamic Universe, we considered big things like stars, galaxies and the Universe itself. Now the Particles and Waves unit brings us to particles so small we need groups of them just to make a single atom. Is there a connection?
To go further, we have to introduce some particle physics vocabulary.
These new elementary particles are part of our Standard Model of how the building blocks of the universe interact with one another. The particles that form “matter” are called fermions, after Enrico Fermi (Fermi has an incredibly long list of things named after him). The fermions are divided into two groups; quarks and leptons, as shown in the diagram below.