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If a wire 30 cm long is extended to 30.5 cm by a force of 300 N. find the strain...


Question

If a wire 30 cm long is extended to 30.5 cm by a force of 300 N. find the strain energy of wire

Options

A) 0.75 J

B) 7.50 J

C) 75.00 J

D) 750.00 J


The correct answer is A.

Explanation:

Energy stored in a stretched wire (strain energy)
= average force x extension
= (1)/2 Fe
= (1)/2 x 300 N (30.5 - 30.0) x 10-2 m
= (300)/2 x 0.5 x 10-2 = 0.75J

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Discussion (3)

  • How did 10 raise to power -2 come in

    1. If you look at the question the length we're given in 'cm' and you should know that the SI Unit for Length is Meter.
      So that 10 raised to the power of -2 is the conversion of the SI Unit to Meter

      Reply
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  • Energy stored in a stretched wire (strain energy)
    = average force x extension
    = (1)/2 Fe
    = (1)/2 x 300 N (30.5 - 30.0) x 10-2 m
    = (300)/2 x 0.5 x 10-2 = 0.75J