9514 1404 393
Answer:
55 8/39 N ≈ 55 N
Step-by-step explanation:
The net force on the 1.4 kg block is proportional to its mass. That is, the ratio of net force on that block to the net force on the total mass is the same as the ratio of the block's mass to the total mass.
net force on 1.4 kg = (1.4 kg)/(1.4 +6.4 kg) × (64 N -15 N) = (7/39)(49 N)
net force on 1.4 kg = 8 31/39 N
Then the force applied by the 6.4 kg mass is ...
64 N - 8 31/39 N = 55 8/39 N ≈ 55 N . . . . applied by 6.4 kg mass
