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Water falls from a height of 60 m at the...

Water falls from a height of `60 m` at the rate `15 kg//s` to operate a turbine. The losses due to frictional forces are `10%` of energy . How much power is generated by the turbine? (g=10 m//s^(2))`.

A

8.1kW

B

10.2kW

C

12.3kW

D

7.0kW

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we will follow these steps: ### Step 1: Identify the given data - Height (h) = 60 m - Mass flow rate (m/t) = 15 kg/s - Gravitational acceleration (g) = 10 m/s² - Losses due to friction = 10% of energy ### Step 2: Calculate the potential energy lost per second The potential energy (PE) lost by the falling water can be calculated using the formula: \[ \text{Power} = \frac{m \cdot g \cdot h}{t} \] Since we are given the mass flow rate (m/t), we can directly use that in our calculation: \[ \text{Power} = \left( \frac{m}{t} \right) \cdot g \cdot h \] Substituting the values: \[ \text{Power} = 15 \, \text{kg/s} \cdot 10 \, \text{m/s}^2 \cdot 60 \, \text{m} \] ### Step 3: Perform the calculation Calculating the above expression: \[ \text{Power} = 15 \cdot 10 \cdot 60 = 9000 \, \text{W} \] ### Step 4: Account for energy losses Since there are losses due to frictional forces which are 10% of the energy, we need to calculate the effective power generated by the turbine: \[ \text{Effective Power} = \text{Power} \times (1 - \text{Loss Percentage}) \] \[ \text{Effective Power} = 9000 \, \text{W} \times (1 - 0.10) \] \[ \text{Effective Power} = 9000 \, \text{W} \times 0.90 \] ### Step 5: Calculate the final power generated Performing the final calculation: \[ \text{Effective Power} = 9000 \times 0.90 = 8100 \, \text{W} \] ### Step 6: Convert to kilowatts To convert watts to kilowatts: \[ \text{Power in kW} = \frac{8100 \, \text{W}}{1000} = 8.1 \, \text{kW} \] ### Final Answer The power generated by the turbine is **8.1 kW**. ---
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