A 9 kg box is moving at a constant speed of 6 m/s to the right of a table. It experiences a leftward force of 13 N and an unknown rightward force.
A. Draw a force diagram describing this situation. Please label all forces.
B. Determine the magnitude of the unknown rightward force. Explain how you know.
I'm getting confused on what equations to use in order to solve for magnitude and other forces, do I also have to use the Kinematic Equations? Or is that only if I'm solving for time, acceleration, etc.