Answer:
Power = 2.5 [W]
Step-by-step explanation:
To be able to solve this problem we must remember that power is defined as the relationship of the work done in a given time interval.

where:
P = power [W] (units of watts)
W = work = 50 [J]
t = time = 20 [s]
Now replacing:
![P=50/20\\P=2.5[W]](https://img.qammunity.org/2022/formulas/physics/college/y3mp1pmzsyydc2hsheyb30oq7yk56hj0l4.png)