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Each of the three blocks P, Q and R show...

Each of the three blocks P, Q and R shown in figure has a mass of 3 kg. Easch of the wires A and B has cross sectional area 0.005 cm^2 and Young modulus `2x10^11Nm^-2`. Neglect friction. Find the longitudinal strain developed ineach of the wires. Take `g=10ms^-2`

Text Solution

Verified by Experts

The correct Answer is:
2
For P, `T_(2)= 3a`
For Q, `T_(1)- T_(2)= 3a`

`rArr T_(1)- 3a= 3a`
`therefore T_(1)= 6a` ...(i)
For R, `3g- T_(1)= 3a`
by putting the value of `T_(1)` from eq (i)
`therefore 3g= 9a rArr a= g//3`
`therefore T_(2)= (3g)/(3) = 10N`
`(delta l_(2))/(l_(2))= (10)/(0.005 xx 10^(-4) xx 2 xx 10^(11)) = (10)/(5) xx 10^(-4)`
`= 2 xx 10^(-4)`
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