The increase in pressure required to decrease the volume of a water sample by $0.2 \%$ is $\mathrm{P} \times 10^5 \mathrm{Nm}^{-2}$. Bulk modulus of water is $2.15 \times 10^9 \mathrm{Nm}^{-2}$. The value of P is _________ .
Answer (integer)
43
Solution
<p>The bulk modulus of a material is defined as:</p>
<p>$ B = \frac{-\Delta P}{\left(\frac{\Delta V}{V}\right)} $</p>
<p>Given:</p>
<p><p>Bulk Modulus, $ B = 2.15 \times 10^9 \, \text{Nm}^{-2} $</p></p>
<p><p>Change in volume percentage, $ \frac{\Delta V}{V} = 0.2\% = \frac{0.2}{100} = 0.002 $</p></p>
<p>To find the required increase in pressure, $ \Delta P $, we rearrange the formula for the bulk modulus:</p>
<p>$ B = \frac{-\Delta P}{- \left(\frac{\Delta V}{V}\right)} $</p>
<p>Plug in the known values:</p>
<p>$ 2.15 \times 10^9 = \frac{\Delta P}{0.002} $</p>
<p>Solving for $ \Delta P $:</p>
<p>$ \Delta P = 2.15 \times 10^9 \times 0.002 $</p>
<p>$ \Delta P = 4.3 \times 10^6 \, \text{Nm}^{-2} $</p>
<p>Since the problem specifies $ \Delta P = P \times 10^5 \, \text{Nm}^{-2} $, we have:</p>
<p>$ 4.3 \times 10^6 = P \times 10^5 $</p>
<p>$ P = 43 $</p>
<p>The value of $ P $ is therefore 43.</p>
About this question
Subject: Physics · Chapter: Properties of Solids and Liquids · Topic: Elasticity
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