Question

In the figure below, m1 = 6 kg, and m2 = 4 kg,. When the system is moving, the tension in the string is observed to be 30 N. What is the coefficient of kinetic friction between m1 and the table top?

Answer 1

$$\mu m_1 g=(m_1-m_2)g-T\\\mu (6)(9.8)=(6-4)9.8+30\\\mu=0.84$$