# Physicopoeia

###### φυσικοποιΐα
THINGS I WISH I'D KNOWN WHEN I STARTED TEACHING PHYSICS

# Several Mechanics Worksheets I've written

Here are a number of mechanics-based worksheets I've written over the years. I usually write these when I'm trying to go beyond the usual stuff you find in books, so they often end up being like longer synoptic exam questions where different ideas from Physics are brought together to lead to a conclusion. I've got answers to all of these: contact me via the Feedback link at the top of the page if you want any.

Motion graphs for a bouncing ball

Drop a ball (golf or table tennis balls work nicely) about 60cm onto a desk and let it bounce three times. Then ask for sketches of distance-time, velocity-time and acceleration-time graphs for the ball's motion, which can be easily sketched on this sheet. Distance-time is easy, but the velocity-time and acceleration-time graphs can really make even the best pupils think.

Principle of Moments Bridge Questions

When doing Principle of Moments with older pupils, it can be tempting not to do much more than the 'see-saw' questions that are standard fare for younger pupils. One subtlety that can be easily overlooked is that the net moment around any point on any object - not just any obvious pivot points - which is not rotationally accelerating must be zero. These questions take you through it and is especially good for pupils who are considering a career in Civil Engineering.

Ion Rockets

I first came across this idea as a very young Star Wars fan (TIE fighters, in case you're interested - TIE standing for Twin Ion Engine). Much later, I found out that they actually exist and are rather useful. For example, they're used to keep nudging geosynchronous satellites back into  in stable orbits. This sheet needs the equation qV which might catch out pupils who are expecting a Mechanics worksheet, so you might want to warn them, or do the first question with them.

Can the astronaut get back safely?

Something of an 'old classic' momentum question, but it doesn't seem to crop up much these days.

Archimedes' Principle

This has been relatively rare on Physics syllabuses, though it does seem to be starting a bit of a comeback in some quarters. Here are two sheets I've done:

The first introduces the concept and asks some old favourite explanation questions based on throwing objects over the side of a boat.

The second involves calculations on a set of balances as an object is lowered into a liquid.

Weightless in a Lift?

Understanding the difference between true weightlessness (which is exceedingly rare and, some would argue, impossible) and apparent weightlessness (which is more common than many pupils will think) is not easy. Most pupils will have noticed the funny feeling you get as a lift moves up and down but might need some help explaining it in correct Physics terms. This sheet is intended to help.

Measuring the frictional forces on a car

Real-life data! This was something I noticed as I commuted to work and realised you could build a few nice components question around it.

Firing guns into the air

You might have seen people doing it, perhaps as a show of strength or celebration in the Middle East, but what are the implications? A nice extension to working on constant-acceleration ('suvat') equations because the acceleration isn't at all constant.

Proving that Father Christmas is Magic

It's been done many times before, but here's a (rather longer than usual) version that calculates the living daylights out of Father Christmas's working life, including the dynamics, present logistics, the calorific content of carrots and both the health and fuel possibilities of sherry. Suitable for mathematically confident younger pupils, or absolutely fine for A-level pupils. This makes for a good 'Christmas lesson' and I've deliberately phrased everything (most notably the title and conclusions) so that I can't be accused of taking the magic away from Christmas.