posted by CR .
Please help ~ Two blocks are arranged at the ends of a massless string as 3.21 kg (box hanging from table)
4.96 kg (box on table). The system starts from rest. When the 3.21 kg mass has fallen through 0.4 m, its downward speed is 1.27 m/s. The acceleration of gravity is 9.8 m/s2 .
What is the frictional force between the 4.96 kg mass and the table?
Answer in units of N.