Final answer:
To find Sally's force in the tug-of-war, Newton's second law is applied, with the rope's mass of 5.0 kg and acceleration of 2.0 m/s^2. Sally must exert a force of 25 N, which accounts for the required net force to achieve the acceleration in addition to Susan's 15 N force.
Step-by-step explanation:
The student's question regarding Susan and Sally's tug-of-war involves calculating the force Sally must exert if the 5.0-kg rope accelerates towards Susan at 2.0 m/s2. To determine this, we use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration (F = ma).
Since Susan pulls with a force of 15 N, and the rope has a mass of 5.0 kg and accelerates at 2.0 m/s2, the net force is the mass multiplied by the acceleration. This gives us a net force of (5.0 kg)(2.0 m/s2) = 10 N. Because acceleration is towards Susan, Sally's force must be greater than Susan's to result in this net force. Therefore, Sally's force would be Susan's force plus the net force, which is 15 N + 10 N = 25 N.