# Physics

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A box of mass m2 = 3.1 kg rests on a frictionless horizontal shelf and is attached by strings to boxes of masses m1 = 1.6 kg and m3 = 2.6 kg as shown below. Both pulleys are frictionless and massless. The system is released from rest. After it is released, find the tension in each string

• Physics -

m1•a=T1-m1•g,
m2•a=T3-T1,
m3•a=m3•g – T3
(m1+m2+m3) •a= T1-m1•g+ T3-T1+m3•g – T3= g• (m3-m1)

a= g• (m3-m1)/ (m1+m2+m3) =9.8•(2.6-1.6)/(1.6+3.1+2.6)=1.34 m/s²
T1=m1• (a+g) = 1.6•(1.34+9.8)=17.8 N
T3 = m3• (g-a) = 2.6(9.8-1.34) = 22 N

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