Question

Masses M₁ , M₂ and M₃ are connected by strings of negligible mass which passes over massless and frictionless pulleys P₁ and P₂ as shown in Figure. The masses move such that portion of the string between P₁ and P₂ is parallel to the inclined plane and portion of the string between P₂ and M₃ is horizontal. The masses M₂ and M₃ are 4.0 kg each and coefficient of kinetic friction between the masses and surfaces is 0.25. The inclined plane makes an angle of 37° with the horizontal.

Answer 1

Constant velocity means net acceleration of the system is zero. Or net pulling force on the system is zero. While calculating the pulling force, tension forces are not taken into consideration. Therefore,

Answer 2

Answer is (a) 4.2 kg, (b) 9.8 N