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confused2009
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Homework Statement
Two blocks connected with a massless rope ,are being dragged by a horizontal force.suppose F= 68N, Mass1= 12 ,Mass2=18kg and coeffecient of fraction between each block and surface is 0.10.
12kg ------T--------18kg-----68N--->
Find tension and magnitude of the aceleration of the system
Homework Equations
f=mg, Fnet= Fa-ff, ff =mu *m*g
The Attempt at a Solution
Now I have tried to sovle it please see if this is correct or I need to change it----> 1st sloving for acceleration of the system Fnet=Ma
Fnet= Fa+Ff
Ff= (0.10)(9.8)(30)
force of friction= 29.4
so Fnet = 68N +(-29.4)
Fnet= 38.6N
acceleration= Fnet/mass
acceleration = 38.6/30= 1.28 m/s^2
This is probably the answer of the second question.
Now sloving for Tension
F=M_1a ( for 1st mass 12kg)
F= 12*1.28m/s^2
Force on 12kgmass= 15.36N
Force of friction 12kgmass= (12)(9.8)(0.10)= 11.76N
Net force on 12 kg mass= 15.36N+(-11.76)= 3.6N
F=M_2a (for 2nd mass18kg)
F= 18*1.28m/1.28m/s^2
Force on 18kg mass= 23.04
force of friction on 18kg mass=(18)(0.10)(9.8)=17.64
net force on 18 kg mass= 23.04N+(-17.64)= 5.4N
Now the net force on 12 kg mass is 3.6N and net force on 18 kg mass is 5.4N.
am I correct so far if yes , is the tension of the rope one of these values or the sum of these values , if one of these which one and why?