In a third-class lever, the input force is applied between the fulcrum and the load, and both move in the same direction. The amount of applied force is always greater than the output force of the load, but the load is moved a greater distance than that over which the input force is applied.
Broadcasts are generally used for several reasons: Address Resolution Protocol (ARP) uses broadcasts to map physical addresses to logical addresses. To build the table of hosts, a device needs to send a broadcast to every other device on the network to essentially find out who is where.
Analog TVs get their signal from an antenna that catches radio air waves from broadcast stations. When the cord to the antenna is not plugged in or you are not on the correct station then the tv will grab whatever air waves it can that are closest to that frequency of station. Because these are random they make a white snow effect.