Three blocks of masses m₁, m₂, and m₃ are connected by massless strings on a frictionless table and pulled by a force T₃ = 40 N. If m₁ = 10 kg, m₂ = 6 kg, and m₃ = 4 kg, the tension T₂ will be:
Find external force F so that block can move on inclined plane with constant velocity. 