An aluminum block of mass m1 = 3.55 kg and a copper block of mass m2 = 7.80 kg a

Question

An aluminum block of mass m1 = 3.55 kg and a copper block of mass m2 = 7.80 kg are connected by a light string over a frictionless pulley. They sit on a steel surface as shown in the figure below, where theta = 40.0 degree. (See the table below for the appropriate coefficients of friction). When they are released from rest, will they start to move? If the blocks move, determine the magnitude of their acceleration. (If the blocks do not move, enter 0.) If the blocks move, determine the magnitude of the tension in the string. (If the blocks do not move, enter 0.) If the blocks do not move, determine the sum of the magnitudes of the forces of friction acting on the blocks. (If the blocks move, enter 0.)

Explanation / Answer

coefficient of static friction is mu_s for copper on steel is = 0.53

then down ward force on copper is m2*g*sin(40) = 7.8*9.81*sin(40) = 49.2 N

static frictional force is fs = mu_s*m*g*cos(40) = 0.53*7.8*9.81*cos(40) = 31.06 N

since 49.2 > 31.06 N,,,then the body slides down ward

A) Yes

B) Net force Fnet = m2*a = m2*g*sin(40)-(mu_k*m2*g*sin(40)) = 49.2-(0.36*7.8*9.81*cos(40)) = 49.2-21.1 = 28.1 N

acclelaration a = 28.1/7.8 = 3.602 m/s^2

C) T -(mu_k*m1*g) = m1*a =

T-(0.47*3.55*9.81) = (3.55*3.602)

T = 29.15 N

D) 0 N

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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