What is the potential energy of a 900 kg rock positioned on a cliff 30 m above the ground?

Ineed extreme for task 2. my student number is 571721. many to whoever solves this correctly, im in debt to you.

Asun-sized star will spend most of its lifetime as a: white dwarf red giant protostar main-sequence star

Afixed electric space heater wired by a cable with an ampacity of 30 a should draw a maximum current of a. 30 a. b. 24 a. c. 15 a. d. 27 a.