To calculate the net force of the system, you need to consider the direction of the forces based on your assignment of negative value to the force moving to the right.
- The cue ball travels to the left with a force of 70 N (positive).
- The four ball moves to the right with a force of 50 N (negative).
Now, you can express the forces:
- Cue ball force = +70 N
- Four ball force = -50 N
To find the net force, you sum these two forces:
\[ \text{Net force} = 70 N + (-50 N) = 70 N - 50 N = 20 N \]
Therefore, the net force of the system is 20 N.