The cosmic background radiation

a. has a blackbody spectrum
b. has its peak emission in the microwave band
c. corresponds to a blackbody at a temperature of 2.726 kelvins
d. all of the above


A

Physics & Space Science

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A 100 kg mass is blown apart into a 60 kg piece and a 40 kg piece. After the blast, the two masses are moving apart with a relative velocity of 60 m/s. The velocity of the 60 kg mass is

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A venturi tube may be used as the inlet to an automobile carburetor. If the 2.0-cm diameter pipe narrows to a 1.0-cm diameter, what is the pressure drop in the constricted section for an airflow of 3.0 m/s in the 2.0-cm section? (? = 1.2 kg/m3.)

a. 70 Pa b. 85 Pa c. 100 Pa d. 120 Pa e. 81 Pa

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Displacement is which of the following types of quantities?

a. vector c. magnitude b. scalar d. dimensional

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What is expression gives the efficiency of an ideal heat engine operating between a higher temperature Th and a lower temperature Tc (both expressed in kelvins)?

a. = 1 + Tc / Th b. = 1 – Tc / Th c. = 1 – Th / Tc d. = 1 – Tc e. = Tc / Th

Physics & Space Science