4blocks(m1,m2,m3,m4)on frictionless surface connect by string-what is T in middle string?

Question

4 blocks m1=25kg, m2=45kg, m3=35kg, m4=25kg sit on frictionless horizontal surface connected block to block by massless string. F1 exerted to left is 67N and F2 exerted to right is 50N. Tension x (Tx) b/w m1 and m2. Ty b/w m2 and m3. Tz b/w m3 and m4. What is Ty?

<---F1____M1__Tx___M2___Ty___M3___Tz___F2--->

Answer 1

Look at FBDs of each block

67-Tx=25*a
Tx-Ty=45*a
Ty-Tz=35*a
Tz-50=25*a

solve for all 4 unknowns

add all of the equations together to get
67-50=(25+45+35+25)*a
a=0.13 m/s^2
Tx=63.7 N
Ty=57.8 N
Tz=53.3 N

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