Question

Two blocks are connected by a massless rope over a massless, frictionless pulley, as shown in the figure. The mass of block 2 is m2 = 10.5 kg, and the coefficient of kinetic friction between block 2 and the incline is μk = 0.200. The angle of the incline is 27.5°. If block 2 is moving up the incline at constant speed, what is the mass m1 of block 1? 

Answer 1

here,

m2 = 10.5 kg

coefficient of friction , u = 0.2

theta = 27.5 degree

when the system is moving at constant velocity

the net acceleration = 0

net force /effective mass = 0

(m2 * g * sin(theta) + u * m2 * g * cos(theta) - m1 * g) = 0

(10.5 * sin(27.5) + 0.2 * 10.5 *cos(27.5) ) = m1

m1 = 6.71 kg

the mass of block 1 is 6.71 kg

Answer 2

(10.5 * sin(27.5) - 0.2 * 10.5 *cos(27.5) ) = m1