Posts Tagged ‘velocity’

I was playing a new update of Doodle Jump on my iPhone this morning and I suddenly thought it would make a pretty cool lesson on motion and it could actually apply to both GCSE and AS Physics, depending how you phrase your questions.

The idea is to find out how high the little alien in Doodle Jump actually jumps. There is no reference in the game to suggest what scale the screen has, so I used Vernier Video Physics and arbitratily set the distance between the block on which the alien was jumping (see video below) and the last but one block above the creature to be 10m.

I then tracked the position of the alien for one jump and the analysis of the velocity graph shows the gradient is not right, i.e. g is not close enough to 10m/s2.

So, I went back and changed the scale to be 4.5m between the two blocks mentioned above. That seemed to have done the

trick, as the gradient of the velocity – time graph in the video below is about 10m/s2.

If you look back at the Displacement – Time graph for the vertical axis, you can now see that the little alien jumps to a height of about 2.3m. That is quite something for a little fella like him.

Obviously, we are assuming the alien is jumping near the surface of the earth, or at least a planet with the same g.

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Last week I finally got round doing something I had wanted to do with my Yr11 classes for a long time. We acted a Displacement – Time graph. This might not sound amazing to you and I have done a similar activity in the past, but this time the difference was that my learners could actually check their outcomes very quickly and without having to guess if their movements reflected the D-T graph faithfully, as they could use what I think is one of the best iPhone/iPad App for Physics, the Vernier Video Physics app!

Indeed, we could have used cameras to record the videos and upload the videos on our laptops to use with Tracker, but the versatility of an iPad and the simplicity of the Vernier Video Physics app made things very easy and intuitive.

So, what’s this activity about? Well, the learners split into groups of 3-4 and analyse the graph below.

Then, they organise themselves to act the graph. So, one person will walk along a straight line to mimic the graph, whilst the others in the group could help signposting important parts of the graph, as well as keeping the time.

You can see how the Vernier Video Physics app renders the video after tracking the object in each photogram. The images at the end are the displacement and velocity analysis after the tracking has been completed!

What do you think? Is this group representing the graph well?

In this Blog I invite you to support my video entry to the O2 Learn Competition for three simple reasons:

1) I believe some of the videos that are winning the Fortnightly stages give a poor representation of Education in Britain

2) Many teachers who have submitted a video are cheating by creating false accounts to gain extra votes

3) The winning videos will be considered by the public as the best in British education, so I believe it is important that good examples are presented

So, if you like my video and you want your viewing to count and rate it, please follow the following instructions:

– Go to this website http://www.o2learn.co.uk and register (top right), or login if you are already registered. Remember you will receive an activation email and sometimes it might end up in people’s junk mail, so please check in there too!

– Login (top right) and click on this link http://bit.ly/o2learnvideo to watch my video

– If you like the video, please rate it by clicking on Rate this video below the video screen and give it 5 stars 🙂

Please remember that you need to be logged in for your viewing and rating to count!

As an educator I believe that engaging in these types of competitions is important to give a good representation of good practice in Education to the public. The teaching profession doesn’t always get a very good reputation from the Media and having good videos in the winning entries can help to change people’s views on teachers and Education in Britain. So, please support my entry only if you think it is a good video that would help learners to understand the topic presented!

Another way in which you could help is by spreading the word and passing on the link to this Blog post to your colleagues, friends, pupils, etc… and ask them to follow the instructions to support my entry.

Thank you in advance for your support and let me know if you are entering a video too, so I can support it!

You must have guessed I have a soft spot for comics and Superheroes by now. So, when @russeltarr (look at his excellent website here) twitted a link to a video made by his 14-years old Historians (as he calls them) I got immediately interested in this new video creator with animated characters; xtranormal.com. Believe me, it is really good fun and very easy and quick to use. The below video took me about 15 min to make and it was a simple attempt to create an example for my Yr 10 pupils, so that they could also use this tool to create fun videos about an area of Physics we have studied (if you can’t see the video from this blog click here). Because we have been amused by the Physics of Superheroes in a number of lessons, I though they would like the video I created to understand and remember the difference between Speed and Velocity!

The intent, however, was never to use this video creator as a teaching tool, but rather as a lovely way to get my pupils engaged with Physics and to get them talking about processes by explaining them through unusual situations (a bit like the Marvel Comic on Momentum).

Unfortunately there were two problems I had not anticipated:

1. To publish your videos you must buy credits

2. Our network let us down for the 1000th time and even this really useful tool was blocked

I might be able to get the IT Technician to unblock it, so the kids can at least use the story board and the effects. But I think I will use this great website to create one of those stories where each group writes a line and the next group continues it, so by the end of the lesson we will have a story about Physics that is created by the whole class. It would be even nicer if this  became a quick revision movie about all the topics covered made with the contribution of the whole class! I will let you know how it goes, but if you have some good stories with Xtranormal, please let us know by adding a comment to this blog post.

Have you ever read a superheroes comic? Watched a superheroes cartoon, or at least watched one of the great Marvel movies? I bet you have done one of these at least once. If you ask you pupils, most of them would go to the cinema to watch these films as soon as they are out and would really enjoy them! What a great opportunity to get some Physics in it.

You might think, what Physics? Superheroes defy Physics and would just reinforce silly misconceptions. And that’s where we need to ask a different question, i.e. what would need to happen in this situation, or with this superhero, to be physically possible?

A good example is X-men 3 (DVD only £3 in Tesco). You can use this very popular film to introduce Momentum. The Juggernaut has a very cool power, i.e. “If he builds any momentum, nothing can stop him”. This sentence is in the maximum security lorry scene, when the Juggernaut gets freed. This power can be used to generate interest in momentum. The Juggernaut had to be confined by being tightly bound with extra strong metal restraints, so you can immediately ask: “What do you think momentum depends on?” Obviously, he cannot be allowed to move, or we would build momentum and become unstoppable. So, momentum depends on the velocity of the Juggernaut. What else then? Well, just look at the guy! He is massive, so momentum also depends on the mass of the Juggernaut. Great you can now introduce the momentum equation.

In the last fight you can add juice to the lesson and make momentum really memorable, although you might also want to mute the rather unkind name this villain gives to Kitty. Here the Juggernaut is featured in an amazing scene where he smashes through lots of people, heavy vehicles and walls, so again you can reinforce the concept by asking what causes the Juggernaut to build so much momentum. Get the kids to think about different ideas, e.g. is it his speed? He doesn’t seem particularly fast when he goes through walls, so it must be his mass. But, although he’s very big, he doesn’t really look like a huge giant. What should happen in the Juggernaut body to make this physically possible? Well, he probably has the ability to change the density of molecules in his body, so that his mass increases greatly and he can build enormous momentum and smash into things.

When he eventually tries to crash into Kitty and the “Cure” , they dodge and the Juggernaut (who actually is quite stupid) crashes into the wall and falls unconscious, because the “Cure” is the boy who has the power of taking away the powers of any mutant who is near him. So, the mass of the Juggernaut must have become less here…

I hope you like this idea and you will share other ideas on the Physics of Superheroes. Please, let me know if you will use this idea and how your pupils responded to it!