posted by Sarah .
Three masses, M1= 4.1 kg, M2= 4.1 kg, and M3= 6.7 kg are made of the same material. They are on a horizontal surface and connected by massless strings. The system accelerates to the right at 2.47 m/s2 due to an external force F pulling on M3. Given that T1 is 20.22 N, calculate the coefficient of kinetic friction mk.
Calculate the magnitude of the force F.