A water hose of internal diameter 20 mm at the outlet discharges 30 kg of water in 60s then what will be the water speed at the outlet. Flow is steady and density of water is equal to 1000 kg m-3?
Correct answer: D. 1.59 m/s
- A. 256 m/s
- B. 345 m/s
- C. 123 m/s
- D. 1.59 m/s
Explanation
To find the speed of water at the outlet, first calculate the volumetric flow rate:Volumetric flow rate = Mass flow rate / Density = 30 kg / 60 s / 1000 kg/m3 = 0.0005 m3/s.Next, calculate the area of the hose outlet using the internal diameter:Area = π × (0.02 m / 2)2 = π × 0.012 = 0.000314 m2.Now, use the formula for speed:Speed = Volumetric flow rate / Area = 0.0005 m3/s / 0.000314 m2 ≈ 1.59 m/s.Thus, the correct speed is approximately 1.59 m/s. The other options are incorrect as they reflect misunderstandings or miscalculations of the flow rate and area, resulting in speeds that are unrealistically high.
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