Some areas of the country do throw the weight in youth competitions. If you or one of your athletes is scheduled to throw in a youth meet, you will need to contact the meet director and check what size weight they will be using for the age group.
In the sense of performing as designed, most radar detectors do detect the presence of police radar in the immediate vicinity of a speeding vehicle. Whether or not that information will actually prevent a driver from receiving a speeding ticket remains to be seen, however.
Many of us are familiar with motion sensors, as they have become a common part of most home security systems. These sensors are much like the motion detectors that open the doors to the grocery store or cause the sinks and toilets in the airport to activate without touch. We see motion-sensing devices everywhere. But how do they work? There are two basic types of motion detecting systems. There are those with active sensors and those with passive sensors. Active sensors send out ultrasonic sound waves and passive sensors detect infrared energy.