Now we do our conversions just like above. 121.779 / 5280 = .023 miles .94 / 60 / 60 = .000261 hours .023 / .000261 = 88.12 mph. So there you have it! How to calculate how fast you throw a baseball without a radar gun and only a stop watch.
IR Receiver and Remote. An IR receiver can detect bursts of infrared light sent by a common remote controller (like for a television), and then output a pattern of high/low signals to a Propeller I/O pin. This quick tutorial will first show you how to wire up the infrared receiver.
Very easily. The GPS receiver measures how long it takes a certain   radio signal to travel from the GPS satellite(s) to itself, and from   that, the receiver calcu â¦ lates the distance. It can do that because it   knows precisely how fast the radio signal travels.