Answer:
20watts
Step-by-step explanation:
Formula for calculating power is expressed as;
Power = Work done/Time
Note that the unit of workdone is Joules
Unit of Time is seconds
Hence the unit of power is Joules/seconds or J/s
Hence if the rate at which energy is used up is 20.0J/s, the power will also be 20J/s or 20watts since they have the same unit.