Answer:
5N
Explanation:
Sean's force is 5N because from the equation of Force, calculating for Sue's acceleration F=MA, A=F/M, A= 15N/5kg = 3m/s²
If Sue's force was 15N and he yielded 3m/s², If sean's accelerate towards Sue at 2m/s², his net acceleration of pull is 1m/s², therefore his force F=Ma = 5kg X 1m/s² + 5N