A block of mass m1 = 42 kg on a horizontal surface is connected to a mass m2 = 1

Question

A block of mass m1 = 42 kg on a horizontal surface is connected to a mass m2 = 18.2 kg that hangs vertically as shown in the figure below. The two blocks are connected by a string of negligible mass passing over a frictionless pulley. The coefficient of kinetic friction between m1 and the horizontal surface is 0.31. (Assume gravity acts toward the +y direction and the +x-axis is parallel to the surface and to the right.)

(a) What is the acceleration of the hanging mass? (Indicate the direction with the sign of your answer.)

(b) Determine the tension in the cord. (Indicate the direction with the sign of your answer.)

Explanation / Answer

mg - T = ma

(18.2 * 9.8) - T = 18.2 * a

T = 178.36 - 18.2 a -------------------(1)

In the horizontal T - mu m g = ma

T - (0.31)(42)(9.8) = (42)a

T - 127.596 = 42 a --------------------(2)

sub (1) in (2)

178.36 - 18.2 a - 127.596 = 42 a

50.764 = 60.2 a

a = 0.843 m/s2

---------------------------------------

T = 178.36 - 18.2(0.843)

T = 163 N

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.