b) If this minimum mass is nudged ever so slightly, it will start being pulled u

Question

b)If this minimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will it have?

Figure shows a block of mass m resting on a 20 degree slope. The block has coefficients of friction 0.78 and 0.49 with the surface. It is connected via a massless string over a massless, frictionless pulley to a hanging block of mass 2.0kg. What is the minimum mass m that will stick and not slip? If this minimum mass is nudged ever so slightly, it will start being pulled up the incline. What acceleration will it have?

Explanation / Answer

a) if not slipping T = 2*9.81

sum forces for block on slope
T - mg sin theta - friction = 0
2*9.81-m*9.81*sin(20) - 0.78*m*9.81*cos(20) = 0
m=1.86 kg

b) for 2 kg block
2*9.81 - T = 2 a
for block on slope
T -1.86*9.81*sin(20) - 0.49*1.86*9.81*cos(20) = 1.86 a
add equation
2*9.81 -1.86*9.81*sin(20) - 0.49*1.86*9.81*cos(20) = 1.86 a+2a
a=1.29

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

---

---

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