An interesting application of the relative motion equations is the experimental determination of the speed at which rain falls. Say you perform an experiment in your car in which you park your car in the rain and measure the angle the falling rain makes on your side window. Let this angle equal 20 degrees. Next you drive forward at 25 mph and measure the new angle to be 70 degrees that the rain makes with the vertical axis. Determine the speed of the falling rain in ft/sec.