Day 68: An Interesting QuizPosted: December 16, 2013
I stole another page from Kelly and set this lab practical up as a quiz. The students were told that I would give them both angles and the starting location of a cart on the steeper ramp; their job was to find a formula giving the location of the cart on the shallower ramp such that the carts hit the end stop at the same time.
This is great as a quiz for three main reasons
- It combines multiple models into an interesting problem
- If students get it wrong, they find out physically and can retry the problem if they have time
- It’s awesome to see physically when they get it right.
The picture below has students in the forefront plugging the given values into their formula to prepare for testing (hence the calculators), and students in the background looking at the solutions (yellow sheets), either they already tested correctly or they got stuck. I had a couple of students nail this who have been struggling. It is extremely satisfying seeing the carts hit in the right place.
***Note: This situation is fairly easy to get ‘right’ doing the wrong physics (or by just guessing with a ratio of angles). I always looked at their papers first, and if their answer was close to correct with the wrong work, I cheated and gave one cart a bit of a push at the release so they didn’t hit at the same time. I confessed this to the students later.