July 31, 2006
#135: Substitute
[[In a class room, the board says “Math” on the top-left corner, and “Mr. Munroe” in the middle. A stick figure is standing in front of it, speaking to the class.]]
Teacher: Miss Lenhart couldn’t be here today, so she asked me to substitute.
Teacher: I’ve put out your test. Please get started.
[[A student in the first row raises the exam paper and says.]]
Student: Mr. Munroe, Miss Lenhardt never taught us this.
Teacher: That’s because Miss Lenhart doesn’t understand how important certain kinds of math are.
Student: But this just looks –
Teacher: This material is more vital than anything you’ve ever learned
Student: But –
Teacher: No buts.
Teacher: This is a matter of life and death.
[[Excerpt from the exam paper.]]
Name: _________
[[A stick figure is standing, hands over head. A velociraptor is running towards it.]]
- The velociraptor spots you 40 meters away and attacks, accelerateing at 4 m
s^2 to its top speed of 25 m
s. When it spots you, you begin to flee, quickly reaching yourtop speed of 6 m
s. How far can you get before you’re caught and devoured?
- You’re at the center of a 20m equilateral triangle with a raptor at each corner. The top raptor has a wounded leg and is limited to a top speed of 10 m
s.
[[A stick figure is shown in the above situation. The picture has a legend “(Not to scale)”.]]
The raptors will run toward you. At what angle should you run to maximize the time you stay alive?
- Raptors can open doors, but they are slowed by them. Using the floor plan on the next page, plot a route through the building, assuming raptors take 5 minutes to open the first door and halve the time for each subsequent door. Remember, raptors run at 10 m
s and they do not know fear.