Answer:
W=588,6J
Step-by-step explanation:
Work done is defined as change in potential energy in this question. The work is done against the gravity, g=9,81N/kg, and for a mass of 20kg to lift it up to 3m approximately 588,6 joules. This result is obtained as follows;
W=m.g.h
Then substitute the given values
W= (20kg).(9,81N/kg).(3.0m)
Multiplying results
= 588,6J