The atmosphere you breathe today is:
A) a primary atmosphere.
B) a secondary atmosphere.
C) mostly composed of hydrogen.
D) mostly composed of oxygen.
B
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Physical Pendulum: A simple pendulum that consists of a small ball of mass m and a massless wire of length L swings with a period T. Suppose now that the mass is rearranged so that mass of the ball was reduced but the mass of the wire was increased, with the total mass remaining m and the length being L. What is true about the new period of swing? (There could be more than one correct choice.)
A. The new period is T because the total mass m has not changed. B. The new period is T because the length L has not changed. C. The new period is greater than T. D. The new period is less than T. E. The new period is T because neither L nor m have changed.
An airplane flies between two points on the ground that are 500 km apart. The destination is directly north of the origination of the flight
The plane flies with an air speed of 120 m/s. If a constant wind blows at 10.0 m/s due west during the flight, what direction must the plane fly relative to north to arrive at the destination? A) 4.78° east of north B) 4.76° east of north C) 85.2° west of north D) 4.78° west of north E) 4.76° west of north
A cubic box with sides of 20 cm contains 2 × 1023 molecules of helium with a root-mean-square (rms) speed of 200 m/s. The mass of a helium molecule is 3.4 × 10-27 kg
What is the average pressure exerted by the molecules on the walls of the container? A) 3.39 kPa B) 1.13 kPa C) 570 Pa D) 2.26 kPa E) 9.1 Pa
Two stars, A and B, have the same emissivity, but the radii and surface temperatures are different with RA = 2 RB, and TA = 0.5 TB. Assuming the temperature of space to be negligible, which star radiates the most energy per unit time?
a. Star A b. Star B c. Both radiate the same amount of energy per unit time. d. More information is needed in order to make a determination.