Hey there! I'll try to provide you with my best answer.
Answer: 24120 N
In physics/science it is more easy to do a calculations using formulas if you really understand it! So to find the resultant force on a rocket, we can use the formula: Resultant force= Force exerted - Weight of the rocket in Earth.
Now we already know the force exerted so we need to find the weight.
The formula for weight is: Weight= Mass * Gravity in Earth
W= 600*9.8
= 5880 N
Now, Resultant force = 30,000 - 5880
R = 24,120 N
Please let me know if I'm correct. I still doubt my answer is right...