The resultant force acting on the balloon is 10,400 N.
The resultant force acting on the balloon is calculated by applying Newton's second law of motion as follows;
F = ma
where;
Mass of the helium gas = density x volume
= 0.18 x 3000
= 540 kg
Total mass of the balloon = 500 kg + 540 kg = 1,040 kg
Resultant force = mg
Resultant force = 1040 x 10 = 10,400 N
Learn more about resultant force here: https://brainly.com/question/25239010