October 21, 2014 by dragonflytraining
- Author: Alessio Bernardeli, @asober
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.