In the very first phase after the big bang, when the Universe was about a microsecond old, space was filled with____
a. high-energy photons
b. protons and antiprotons
c. protons, neutrons, electrons, and positrons (anti-electrons)
d. electrons, and positrons (anti-electrons)
e. protons, neutrons, electrons
a
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A two-shell-four-tube-pass heat exchanger has an overall heat exchanger conductance of 350 W/m^2?K and is used to cool 10 kg/s of engine oil from 180ºC to 80ºC. If water at 20ºC is used to cool the oil and the water temperature leaving the heat exchanger is 60ºC, determine (a) mass flow of water required and (b) surface area of the heat exchanger.
What will be an ideal response?
Thermal Expansion: The volume coefficient of thermal expansion for gasoline is 950 × 10-6 K-1. By how many cubic centimeters does the volume of 1.00 L of gasoline change when the temperature rises from 30°C to 50°C?
A. 6.0 cm3 B. 12 cm3 C. 19 cm3 D. 37 cm3
The cork in a bottle is 2.00 cm in diameter. If the pressure inside the bottle is 3.00 atm, then the net force on the cork due to the pressure difference is
A. 37.5 N. B. 45.5 N. C. 48.9 N. D. 55.3 N. E. 63.8 N.
A current can be made to flow in a wire if
a. it is connected to a battery c. a magnet is put into motion near it b. it is put into motion near a magnet d. all of the above