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The heavier block in an atwood machine h...

The heavier block in an atwood machine has a mass twice that of the lighter one. The tension in the string is 16.0 N when the system is set into motion. Find the decrease in the gravitational potential energy during the first second after the system is released from rest.

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Verified by Experts

The correct Answer is:
A
Given, T=16N
from the freebody diagrams
`t-2mg+2ma=0`…..i
`T-mg-ma=0` ………..ii
From equation i and ii
T=4ma`
`rarr a=T/(4m)=4/m m/s^2`

`Now, S=ut+1/2 at^2`
`=(1/2)xx4lmxx1`
`=(2/m)m [because =0]`
Net mass`=2m-m=m`
Decrease in P.E. `=mgh`
`=mxxgx(2/m)`
`=9.8x2=19.6J`
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