Q1 has 50 electric field lines radiating outward and Q2 has 250 field lines converging inward. What is the ratio Q1/Q2?

a. 5
b. ?5
c. 1/5
d. ?1/5
e. 0


d

Physics & Space Science

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The average Reynolds number for air passing in turbulent flow over a 2-m-long flat plate is 2.4 x 106. Under these conditions, the average Nusselt number was found to be equal to 4150. Determine the average heat transfer coefficient for an oil having thermal properties similar to those in Appendix 2, Table 18 at 30°C at the same Reynolds number and flowing over the same plate.

GIVEN
Turbulent flow of air over a flat plate
Average Reynolds number (ReL) = 2.4 x 106
Plate length (L) = 2 m
Average Nusselt number (Nu) = 4150

FIND
Average heat transfer coefficient


ASSUMPTIONS
Steady state
Fully developed turbulent flow
Transition from laminar to turbulent flow occurs at Rex = 5 x 105

SKETCH


PROPERTIES AND CONSTANTS
From Appendix 2, Table 18, for oil at 30°C
Thermal Conductivity (k) = 0.11 W/(m K)
Kinematic Viscosity (v) = 15.4 ? 10–6 m2/s
Thermal Diffusivity (a) = 707 ? 10–10 m2/s

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Observations indicate that it takes Saturn longer than Jupiter to complete one orbit about the Sun. This is in agreement with which of Kepler's laws?

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When a rocket ship gaining speed in remote, gravity-free outer space runs out of fuel, it

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Physics & Space Science