# Example problem — Projectile motion

When I wrote how I plan to make exam questions un-googleable, what I probably should have said was less googleable. Let’s go with that instead.

Let’s try an example of a problem that is “less googleable”. Here’s what I want to start with:

Problem: Lisa throws a stone horizontally from the roof edge of a 50.0 meter high dormitory. It hits the ground at a point 60.0 m from the building. Find the time of flight.

This problem is actually quite googleable, and I’m quite certain the solution and answer are all over the internet. But, just to be sure, here’s my solution and answer:

But, I wouldn’t be asking for the solution to the problem. Instead, I might ask for the following:

1. Motion diagrams
2. Graphs of position vs. time, velocity vs. time, acceleration vs. time

I might also ask for student to:

• Explore the range of possible values for given quantities.

For this example, I’m going to look at the range of values that the stone might be able to go horizontally. If there is no initial velocity in the horizontal direction…

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Physics professor with research interest in musical acoustics