Soru
CHECKPOINT 1.Use Stokes' law to calculate the viscous drag on a ball bearing with a radius of I mm, falling at. 1mms^-1 through liquid chocolate at 30^circ C
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Usta · 5 yıl öğretmeni
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Cevap
To calculate the viscous drag on a ball bearing using Stokes' law, we need to know the radius of the ball bearing, the velocity of the ball bearing, and the viscosity of the liquid chocolate.Stokes' law states that the viscous drag on a spherical object moving through a viscous fluid is directly proportional to the radius of the object, the velocity of the object, and the viscosity of the fluid, and inversely proportional to the radius of the object.The formula for Stokes' law is:F = 6πηrvwhere F is the viscous drag, η is the viscosity of the fluid, r is the radius of the object, and v is the velocity of the object.Given that the radius of the ball bearing is 1 mm and the velocity is 1 m/s, we need to find the viscosity of the liquid chocolate at 30°C.The viscosity of a fluid is a measure of its resistance to flow, and it can vary with temperature. For liquid chocolate, the viscosity at 30°C is approximately 2.5 mPa·s.Now we can plug in the values into the formula:F = 6πηrvF = 6π(2.5 mPa·s)(1 mm)(1 m/s)F = 6π(2.5 × 10^-3 Pa·s)(1 × 10^-3 m)(1 m/s)F = 6π(2.5 × 10^-6 N·s)F ≈ 7.85 × 10^-6 NTherefore,ous drag on the ball bearing is approximately 7.85 × 10^-6 N.