Question

Is it possible to accurately approximate the speed of a passing car while standing in the protected front hall of the school?

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!

Answer 1

I am probably completely wrong but....

Explanation:

I tried to think of absurd stuff such as stroboscopic systems, Doppler effect or radar/sonar mechanism....and I got nothing....:-(
The only thing I can think of it is as follows:

You can only measure directly the distance `d` from the road....BUT you can then measure an angle `theta` (inside the hall using a Goniometer) and using trigonometry evaluate `s` as:

`s/d=tan(theta)`

[ Goniometer ]

So we know the distance between two points `A` and `B`.
We now need to measure the time elapsed from `A` to `B`.
I would set two narrow paper tubes pointing at `A` and `B` to see when the car is passing by the two points and start/stop the chronometer.

Once you have the time `Deltat` between `A` and `B` we evaluate the speed as:

`"speed"=s/(Deltat)`

Let me know what you think....