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The heart of a man pumps 5 liters of blo...

The heart of a man pumps 5 liters of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be `13.6xx10^(3) kg//m^(3)` and `g=10 m//s^(2)` then the power of heat in watt is :

A

1.7

B

2.35

C

3

D

1.5

Text Solution

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The correct Answer is:
To solve the problem, we need to calculate the power of the heart in watts based on the given parameters. Here’s a step-by-step breakdown: ### Step 1: Convert the volume of blood pumped per minute to cubic meters per second The heart pumps 5 liters of blood per minute. We need to convert this to cubic meters per second. \[ \text{Volume per minute} = 5 \text{ liters} = 5 \times 10^{-3} \text{ m}^3 \] Since there are 60 seconds in a minute, we divide by 60 to convert to cubic meters per second: \[ \frac{dV}{dt} = \frac{5 \times 10^{-3} \text{ m}^3}{60 \text{ s}} = \frac{5}{60} \times 10^{-3} \text{ m}^3/\text{s} = \frac{1}{12} \times 10^{-3} \text{ m}^3/\text{s} \approx 8.33 \times 10^{-5} \text{ m}^3/\text{s} \] ### Step 2: Convert the pressure from mm of mercury to pascals The pressure is given as 150 mm of mercury. We need to convert this to pascals (Pa). Using the formula: \[ P = \rho g h \] Where: - \(\rho\) (density of mercury) = \(13.6 \times 10^3 \text{ kg/m}^3\) - \(g\) (acceleration due to gravity) = \(10 \text{ m/s}^2\) - \(h\) (height in meters) = \(150 \text{ mm} = 0.15 \text{ m}\) Calculating the pressure: \[ P = 13.6 \times 10^3 \text{ kg/m}^3 \times 10 \text{ m/s}^2 \times 0.15 \text{ m} = 20400 \text{ Pa} \] ### Step 3: Calculate the power of the heart Power can be calculated using the formula: \[ \text{Power} = P \times \frac{dV}{dt} \] Substituting the values we have: \[ \text{Power} = 20400 \text{ Pa} \times 8.33 \times 10^{-5} \text{ m}^3/\text{s} \] Calculating the power: \[ \text{Power} = 20400 \times 8.33 \times 10^{-5} \approx 1.70 \text{ W} \] ### Final Answer The power of the heart is approximately **1.70 watts**. ---

To solve the problem, we need to calculate the power of the heart in watts based on the given parameters. Here’s a step-by-step breakdown: ### Step 1: Convert the volume of blood pumped per minute to cubic meters per second The heart pumps 5 liters of blood per minute. We need to convert this to cubic meters per second. \[ \text{Volume per minute} = 5 \text{ liters} = 5 \times 10^{-3} \text{ m}^3 \] ...
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