28. What is the value of a resistor in a series circuit if you measure 0.5 amps flowing through it and 15 volts across it?
29
A lightbulb using 120 V and 1 A is using how many watts?
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tarm with the correct definition

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

At 12 noon, the count in a bacteria culture was 400; at 4: 00 pm the count was 1200 let p(t) denote the bacteria cou population growth law. find: (a) an expression for the bacteria count at any time t (b) the bacteria count at 10 am. (c) the time required for the bacteria count to reach 1800.

Find the kinematic pressure of 160kpa. for air, r-287 j/ kg k. and hair al viscosity of air at a temperature of 50°c and an absolute (10 points) (b) find the dynamic viscosity of air at 110 °c. sutherland constant for air is 111k