Is it possible to accurately approximate the speed of a passing car while standing in the

protected front hall of the school?
Task: Determine how fast cars are passing the front of the school. You may only go
outside to measure the distance from where you are standing to the road. All
other measurements must be taken from inside the building (I want you to stay
warm and dry!). Make sure to clearly explain your process to gauge the speed of
passing cars and submit all of your work!

1 answer

Well, if you were a boat navigator you would use the 45 degree trick.
Measure that distance from you to that road. That distance, d, should be perpendicular to the road. Now look 45 degrees right (or left). The distance along the road to that point on the road from your original point is that same d (45,45, 90 triangle so d, d and d sqrt 2)
so now you know the distance between those two points on the road without ever going to the second one. Now you just time the car between points and speed = distance/time
We use that in reverse to see how far from the lighthouse we are. (45 off bow, 90, distance travelled = distance off land.