What is the name for a star and planets held together by gravity? a. solar system b. galaxy c. black hole d. supernova

Ineed the answers for these promblems i have

Acaterpillar tries to climb straight up a wall a meter high, but for every 2 cm up it climbs, it slides down 1 cm. eventually, it reaches the top. when it reaches the top, it does not pull itself over so it will slide down 1 cm. what is the total displacement traveled?

Which type of energy would have nothing to do with ironing clothes? a. heat b. chemical c. electrical d. mechanical