The Physics Teaching Podcast

Tag: forces

  • Newton’s Laws for Non-Specialists

    Newton’s Laws for Non-Specialists

    So fundamental… such a minefield. Newton’s laws are central to school physics and so can be daunting for those heroes who teach physics but would not describe physics as their specialism. Even as specialist physics teachers, Thomas and Robin have struggled with “reaction”, free body diagrams and force arrows so it was great to welcome physics coach, teacher educator and veteran of “S1E1” Jessica Rowson joins us to put things right.

    Jessica is a teacher educator and senior lecturer at St Mary’s Twickenham, as well as Teaching and Learning Coach for the Ogden Trust. If you need any help with science / physics teaching or CPD, she can be contacted via the links below.

    Jessica, Thomas and Robin had a suggested teaching order as follows. You can find links to help you on the specifics below, as well as some useful forces resources

    • Start with the idea of a force as a ‘push or pull’
    • Introduce and explore force arrows that reflect both magnitude of the force (length of arrow) and the direction of the force (where arrow is pointing).
    • move on to sketching common objects and forces on them (Free Body Diagrams). Be careful to get students to abstract objects to ‘blobs’ before you lose a lot of time with artistic renditions of bikes or Ferraris).
    • Now on the laws themselves – start with Newton’s 3rd.
    • MISCONCEPTION ALERT: there is often confusion between normal supporting force and reaction force as described in Newton’s 3rd.
    • It’s vital to be clear on the wording of Newton’s 3rd: if object A exerts a force on object B, then object B exerts an equal and opposite (reaction) force on object A of the same type.
    • Spend some time working on the misconceptions around newton’s 3rd with plenty of examples.
    • Move on to Newton’s 1st law and the idea that a resultant force results in a change in motion.
    • MISCONCEPTION ALERT: Students will believe that a moving object has a force acting on it. This dies hard and so lots of examples needed here! Look at the BEST resources in the links section for some help!
    • Address the idea that objects on earth slow down and stop BECAUSE they always have resistive forces (friction or air resistance) acting on them.
    • Lastly, address Newton’s 2nd law where we can work out the change in motion that a resultant force causes.
    • We recommend introducing the iconic formula in the form a=F/m. Why? The acceleration is the change in motion, and can be quantified as the ratio of force to mass.

    Jess finishes with a description of a great experiment that will help students to think through the ideas of forces: any experiment involving a radio controlled car must be a winner.

    Thomas’ PowerPoint on Newtons-Third-LawDownload

    Links

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

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  • IoP Domains

    IoP Domains

    Thomas and Robin mull over the recent Nobel Prize for Physics, then chat to Carole Kenrick about IoP Domains and zines.

    The Nobel Prize is still the ultimate accolade and viewed with envy by the fields that don’t have a Nobel Prize (in your face, maths!). This week we start by congratulating the three winners of the 2020 physics prize: Roger Penrose, Reinhard Genzel, and Andrea Ghez.

    We catch up with Carole Kenrick (sadly without Benji the cat – see episode 8 of season 1 – he was hungry and had to be banished). Carole tells us about IOP Domains – a distillation of CPD resources made by our great friends and former colleagues at IOP. Links are below, and well worth checking out if you are teaching some physics and would like a bit of focused, high-quality CPD presented by some of the best in the business, then check out domains from IOP!

    Carole also introduced us to ‘Zines’ – short sharp publications that raise awareness of breadth and diversity in physics – sadly aspects of the subject that are often neglected! Carole tells us how we can turn this into a game format that can engage students and teachers and raise awareness by stealth.

    We reflect on how we have changed practice for the better – even amongst all the disruption of Covid – thanks to your tips and generous sharing of practice so a warm and heartfelt thank you. If you do have anything that you think might benefit the physics teaching community, please don’t hesitate to get in touch.

    Links

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

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  • Force or False (Forces @ Primary School)

    Force or False (Forces @ Primary School)

    Ex -colleague and ex-colleague Andy Harrison is writing a scheme of work for Primary Science and asks Thomas and Robin to help him with his understanding of forces.

    S02E09 Timestamps

    • What’s a force? @ 02:40
    • Gravity @ 04:20
    • Electrostatics @ 08:20
    • Reaction/Support force @ 17:30
    • Energy @ 21:12

    Summary

    Ex-colleague Andy Harrison reached out to Robin last week for some help. Andy, a Biologist, is no longer in the classroom but working as an Outreach Officer for a medical research organisation. Andy has been working with Primary Schools and is working on a scheme of work around Forces. Sensing an opportunity for a podcast Robin and Thomas hooked up the microphones and off we went.

    Andy is working on a task that might be called “Force or False” where the pupils have to state whether something is a force or not. Amongst other questions, we talked about Is Fire a force? Is Pressure a Force? Is Gravity a Force? We also appealed for some ideas that could be used for practicals in primary science. You know the kind of thing, minimal specialist equipment required but allow primary students to practise their practical skills (e.g. modelling; conducting a fair test etc.).

    Alom Shaha’s fine book gets another mention and can be found here. If you are looking to liven up your science lessons in primary school, this is a great source of ideas that won’t break the bank.

    N.B. We haven’t forgotten Charlie, we’ve just forgotten to include his latest update. It will be in the next episode.

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

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  • Teaching Forces to 11 Year olds

    Teaching Forces to 11 Year olds

    Thomas and Robin try something else new. Discussing how they would teach the first three lessons on Forces to 11 year olds.

    Timestamps

    • IoP Spark @ 00:37
    • How would you teach forces to 11 year olds? @ 05:00
    • Guidance for a non-specialist @ 21:10

    Summary

    Robin and Thomas were back to basics this week.  With Patrick busy bringing physics joy to a new generation of New Hampshirites (that’s really what residents of New Hampshire are called – I Googled it and everything), it was just the two physics geeks getting together to talk forces.

    Before we got to the main business we had time to welcome IOP’s new Spark website which gathers together and updates the resources offered to teachers by the IOP.  With a new section on misconceptions and a much slicker look and feel, IOP Spark should be in every physics teacher’s bookmarks – have a look at spark.iop.org.

    If you completed our listener survey, a big thank you!  The results show that you love the Podcast, and particularly those episodes where you get tips and pointers for teaching specific topics, and so this week we zeroed in on KS3 Forces, with TWP asking the question, “What would your first three lessons be for introducing forces in year 7 or 8?”

    We discussed starting with the idea of a “push, pull or twist” and asking students to think about ways this might work.  TWP uses a circus of different types of forces to get students thinking about pushes, pulls and twists and discussing the origins of different types of forces.

    A common misconception is that movement requires a force (e.g. a tennis ball travelling over the net ‘must’ have a force that makes it move forward).  This is not true, and Robin said that he would like students to have been introduced to the idea that persistent motion is the natural state and that our experience of friction and drag make us think that objects slow down and stop.

    Another concept to introduce is force arrows – an arrow in the direction of the push, pull or twist, and whose length is proportional to the size of the force.  Robin suggested re-visiting the earlier circus and asking students to add force arrows to their earlier observations.

    It is one area when lots of practical investigation can aid understanding, particularly on the idea of resistive forces such as friction and drag.

    Don’t forget to tell us how it goes and share your tips.  Details on how to get in touch are below. Thanks for listening.

    Chit

    Thomas’ Carousel on Forces might include the following:

    • a boat (origami will do) floating in a tub of water
    • ping pong ball with two straws and a zig zag obstacle course made with text books
    • popping toy
    • something static like a heavy weight on a piece of paper
    • wind up toy
    • flannel to wring out
    • pendulum
    • pull along toy
    • weight hanging on a spring
    • anything you can think of that pushes, pulls or twists!

    Join in!

    Please share ideas or successes – or indeed questions by messaging us on BlueSky: https://bsky.app/profile/physicstp.bsky.social .  You can also message us via our website contact form on every page of the web site at  the.physicsteachingpodcast.com, or email using the address given in the podcast (if we remember). We are moving away from X but can be found there as @physicstp.

    Music

    The music is used under the Attribution-NonCommercial 3.0 International License