Question

A mass m is attached to a thin wire and whirled
in a vertical circle. The wire is most likely to break
when :
(1) the wire is horizontal
the mass is at the lowest point
inclined at an angle of 60° from vertical
the mass is at the highest point
hacinhon
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Answer 1

answer : The mass is at the lowest point

explanation : you should remember that wire is most likely to break only when tension acting on wire will be maximum.

as you know, tension acting on the wire at the lowest point will be maximum.

mathematically you can derive it.

wire is at the lowest point,

T - mg = mv²/r => T = mg +mv²/r

wire is at highest point,

T + mg = mv²/r => T = mv²/r - mg

wire is horizontal,

T = mv²/r

wire inclined at an angle 60° from vertical line,

T - mgcos60° = mv²/r => T = mgcos60° + mv²/r

you can see, only at lowest point, wire is most likely to break .