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If work done in stretching a wire by 1 mm is 2J. Then the work necessary for stretching another wire of same material but with double the radius and half the length by 1 mm in joule is

A. ¼
B. 4
C. 8
D. 16

User Aprock
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1 Answer

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Final answer:

The work necessary for stretching another wire of the same material but with double the radius and half the length by 1 mm is B. 4 J.

Step-by-step explanation:

To find the work necessary for stretching another wire of the same material but with double the radius and half the length by 1 mm, we can use the formula for work:

Work = Force × Displacement

Since the wire is being stretched by 1 mm, the displacement is 0.001 m. The force can be calculated using Hooke's law:

Force = spring constant × displacement

Now, let's consider the differences in radius and length between the two wires:

- The second wire has double the radius: If the radius of the first wire is r, then the radius of the second wire is 2r.

- The second wire has half the length: If the length of the first wire is L, then the length of the second wire is L/2.

Therefore, the spring constant of the second wire is:

spring constant = (spring constant of first wire) × (radius of second wire / radius of first wire) × (length of second wire / length of first wire)

Now we can plug in the values:

spring constant = (2 J / 0.001 m) × (2r / r) × (L / (L/2)) = 4 J

Finally, we can calculate the work for stretching the second wire:

Work = Force × Displacement = (4 J) × (0.001 m) = 0.004 J

Therefore, the work necessary for stretching another wire of the same material but with double the radius and half the length by 1 mm is 0.004 J, which is equal to 4 J.

User Adel Mourad
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