Question

Question 7 4 points Save Answer Two blocks are connected over a massless, frictionless pulley as shown in the figure below. The mass of block 2 is 11.7 kg, and the coefficient of kinetic friction between block 2 and the incline is 0.200. The angle 8 of the incline is 35.5 If block 2 is moving up the incline at constant speed, what is the mass of block 1? Friction a.8.7 kg b. 10.0 kg O C 11.4 kg d 14 2 kg

Answer 1

Given blocks are moving with constant speed, so acceleration =0

Consider Block 1

Net Force=Mass*acceleration

$T-m_{1}g=m_{1}a=0$

${\color{Red} T=m_{1}g}$ ------------(1)

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Consider Block 2

Net Force=Mass*acceleration

$T-m_{2}gsin35.5-Fr =m_{2}a=0$

$T-m_{2}gsin35.5-\mu N =0$

$T-m_{2}gsin35.5-\mu m_{2}gcos35.5=0$

$T-11.7kg*9.81*sin35.5-0.2*11.7kg*9.81*cos35.5=0$

$T-66.65-18.69=0$

${\color{Red} T=85.34N}$

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From (1)

${\color{Red} T=m_{1}g}$

$85.34N=m_{1}*9.81m/s^{2}$

${\color{Red} m_{1}=8.7kg}$

ANSWER: Option a. 8.7 kg

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