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A block of mass 5 Kg accelerates from re...

A block of mass 5 Kg accelerates from rest to a velocity of 10 m/s in 10s under the influence of an external force. What is the work done by the external force?

Text Solution

Verified by Experts

From the free body diagrams
`T+15a-15g=0`
`rarrT=15g-15a`..i
`Now T_1 -5g-5a=0`
`rarr T_1=5g+5a`
Again `T-(T_1+5a+mR)=0`
`rarr T-(5g+5a+5a+mR)=0` ……..ii
From equaton i and ii
`15g-15a=5g+10a+0.2(5g)`
`rarr `25a=+90` [g=10]
`rarr a=3.6m/s^2`
From equation ii, `T=5xx10+10xx3.6+02x5xx10`
`=96N` inthe left string
From equation iii,
`T=5g+5a`
`=5xx10+5xx36`
=50+18
=68N in theright stirng.
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