I've just completed my 1000th multiple choice question for studyib. This isn't actually the 1000th but it's a good example.

The springs all have the same original length as the one on the left. The red springs have half the spring constant of the blue ones.

Which ball goes highest?

The image is from an Algodoo simulation and the solution contains an animation to show what happens.

It's not easy writing 1000 questions especially when they have to be different to the 1000+ you've written elsewhere (here and for my ebook). One problem is there have to be 4 sensible options and you often end up with only 3, up, down stays still, bigger, smaller, equal. One trick is to combine 2 variable, A gets bigger B gets smaller. Making animations and images takes time but you can use the same one for many questions. My record is 13 questions for this image

The questions are a part of the SL/HL core revision website studyib.net which also includes over 300 videos 80 interactive learning networks, over 250 flashcards and a multiple choice question app.