A Nepali two-rupee coin has a diameter of 1.5000 m. The coin is made of a metal alloy (mostly zinc) for which the coefficient of linear expansion is [tex]2 \times 10^{-5} \, ^{\circ}C^{-1}[/tex]. What would the diameter be on a hot day in Bhairahawa? Write your answer to four decimal places.



Answer :

Sure, let's solve this problem step by step.

1. Given Data:
- Initial diameter of the coin, [tex]\( D_0 = 1.5000 \)[/tex] meters.
- Coefficient of linear expansion, [tex]\( \alpha = 2 \times 10^{-5} \, \text{°C}^{-1} \)[/tex].
- Temperature change, [tex]\( \Delta T = 1 \, \text{°C} \)[/tex] (Assumed).

2. Calculate the change in diameter ([tex]\( \Delta D \)[/tex]):
The formula to determine the change in diameter due to thermal expansion is:
[tex]\[ \Delta D = D_0 \times \alpha \times \Delta T \][/tex]

Plugging in the values:
[tex]\[ \Delta D = 1.5000 \times 2 \times 10^{-5} \times 1 \][/tex]

3. Determine the change in diameter ([tex]\( \Delta D \)[/tex]):
The calculation yields:
[tex]\[ \Delta D \approx 0.0000 \, \text{meters} \][/tex]

4. Calculate the new diameter ([tex]\( D \)[/tex]):
The new diameter is the initial diameter plus the change in diameter:
[tex]\[ D = D_0 + \Delta D \][/tex]

Given that:
[tex]\[ D = 1.5000 + 0.0000 \][/tex]
[tex]\[ D \approx 1.5000 \, \text{meters} \][/tex]

5. Final Answer:
The diameter of the Nepali two rupee coin on a hot day will be approximately [tex]\( 1.5000 \)[/tex] meters, accurate to four decimal places.