1.
I was driving on Interstate 90 and noticed in my rear view mirror a car that was rapidly
approaching. I look at my speedometer and saw that I was going 72 miles per hour (I had my
cruise control on). When the fast car passed me, I looked at my watch and began to count the
number of seconds that had passed. I saw a bridge in the distance. When I reached 11 seconds,
the fast car drove past the bridge. I continued to count and at 12 seconds, I drove past the same
bridge.
How fast (miles per hour) was the other car going?
Solution
v*11=72*12
==> v=78.545 mi/hr