Two football players have a head-on collision and grab onto each other's uniforms. The 80 kg Pennridge Ram was moving at 3 m/s, while the 70 kg Souderton player was moving in
the opposite direction at 2.5 m/s. What is their final velocity after impact?

The speed of a sound wave depends on what type of medium it is traveling through, and if that medium is a gas or liquid, a significant change in temperature can also affect its speed. In air, the speed at which sound travels is about 1 mile every 5 seconds at 32 degrees Fahrenheit, but the speed of a sound wave traveling through solid rock is about 18 miles every 5 seconds. Sound travels faster through a solid substance like rock because, unlike liquids or gases, the molecules in a solid are held close together