A brick is attached to a spring balance as 
You pull the brick (a)without wrapping polythene on it and
(b)by wrapping polythene on it.Discuss the reading in the two cases.
Very urgent please

Two cases may occour :
If the brick is hanged then no change in the scale will be shown in the scale.
However if the brick is placed on a surface, say a table , then the spring balance will record more force than when the brick is wrapped in a polythene , which means that the polythene would offer a lesser force of friction than the brick itself.
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Like my answer please , will you ?
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pull the bric using a spring balance,by applying some force.after wrapping the brick in a polythene bag.
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