How much work is done in holding a 500 N barbell motionless above your head for 30 s?

Ifound this on google “how does an observation of an object differ from an inference about it? observations uses one or more of the senses to gather in formation and record it but an inference is a logical interpretation of the prior knowledge like testing samples.” i hope this you for what your looking for. can you plz mark me brainliest?

It should be d if not then c

Iwould say earthquakes.