Why do we have to poop?

When barack obama was running for president, at a campaign stop he tried to bowl, something he isn't very good at. the media loved it because he threw a gutter ball while they were all watching. this is an example of:

Frequency of electromagnetic waves that a radio station is assigned. what do you call this type of wave?

Describe the work performed by a ski lift in terms of kinetic and gravitational potential energy