Block A (Mass = 3.699 kg) and Block B (Mass = 2.890 kg) are attached by a massle
ID: 1592704 • Letter: B
Question
Block A (Mass = 3.699 kg) and Block B (Mass = 2.890 kg) are attached by a massless string as shown in the diagram.
Block A sits on a horizontal tabletop. There is friction between the surface and Block A. The string passes over (you guessed it) a frictionless, massless pulley. Block B hangs down vertically as shown. When the two blocks are released, Block B accelerates downward at a rate of 2.250 m/s2. What is the tension in the string?
What is the magnitude of the force of friction acting on Block A?
What is the coefficient of friction between the tabletop and Block A?
Tries 0/10Explanation / Answer
(1) The equilibrium equation for block B is,
mg - T = mBa
T = mBg – mBa
T = 2.890*(9.81-2.250)
T = 21.84 N (answer)
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(2. The magnitude of the force of friction acting on Block A is,
T - Friction = mA
Friction = T - mAa
Ff = 21.84 - (3.699 *2.25)
Ff = 13.51 N (answer)
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(3) The coefficient of friction between the tabletop and Block A is,
Friction = u m g
Ff = u = 13.51 /(3.699 *9.81)
u =0.372 (answer)