At any time, approximately 20 volcanoes are actively erupting on the Earth, and 50–70 volcanoes erupt each year. Over the past 100 years, an average of 850 people have died each year from volcano eruptions. As scientists and engineers study the mechanics of lava flow, accurately predicting the flow rate (velocity) of the lava is critical to saving lives after an eruption. Jeffrey’s equation captures the relationship between flow rate and viscosity as: where ρ is the density of the lava, g is gravity, t is the flow thickness, α is the slope, and m is the lava viscosity. Typical values are given as follows for the flow rate: m= 4x103 kg/(m.s) ±1% ρ= 2.5 g/cm3 ±1% t= 28 cm ±0.5 cm α= 10° ±1 ° g= 9.81 m/s²

At any time, approximately 20 volcanoes are actively erupting on the Earth, and 50–70 volcanoes erupt each year. Over the past 100 years, an average of 850 people have died each year from volcano eruptions. As scientists and engineers study the mechanics of lava flow, accurately predicting the flow rate (velocity) of the lava is critical to saving lives after an eruption. Jeffrey’s equation captures the relationship between flow rate and viscosity as: where ρ is the density of the lava, g is gravity, t is the flow thickness, α is the slope, and m is the lava viscosity. Typical values are given as follows for the flow rate: m= 4x103 kg/(m.s) ±1% ρ= 2.5 g/cm3 ±1% t= 28 cm ±0.5 cm α= 10° ±1 ° g= 9.81 m/s²

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.13P: 5.13 The torque due to the frictional resistance of the oil film between a rotating shaft and its...

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