IIT JEE past question Mechanics.

Two point masses m1 and m2 are coupled by a spring of spring constant k and uncompressed length L0. The spring is fully compressed and a thread ties the masses together with negligible speration between them. the tied assembly is moving in the +x direction with uniform speed v0.

At a time say t=0, it is passing the origin and at that instant the thread breaks. The masses, attached to the spring start oscillating.

The displacement of mass m1 is given by x1(t)=v0t-A(1-cosωt) where A is a constant

Fidn
1) displacement x2(t) of mass m2

ii) the relationship between A and L0

3 Answers

1
Ghosty ·

v1(t)=v0-Aωsin(ωt)

m2v2(t)+m1v1(t)=(m1+m2)v0

m2v2=m1v0+m2v0-m1v0+m1Aωsin(ωt)
v2=v0+m1/m2Aωsin(ωt)

dx/dt=v0+m1/m2Aωsin(ωt)

0∫xdx=0∫tv0+m1/m2Aωsin(ωt)dt

x2(t)=v0t-m1/m2Acos(ωt)+m1A/m2

x2(t)=v0t+m1/m2A(1-cos(ωt))

3
iitimcomin ·

oh!!!!! thanx for postin ques. bhiyya didnt see it bfr and i went offline ..............

3
iitimcomin ·

since part i is solved lemme try 2 ...........

x2 - x1 max = 2(m1 - m2)/m2 A .......................

1/2 of it shud be the natural length of spring as x2-x1 min =0

m1-m2/m2A = Lo

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