Florence, who weighs 120. lbs, stands on a bathroom scale in an elevator. What will the scale read when the elevator is accelerating downward at 2.0 m/s2?
A) 86. lb
B) 1.4 102 lb
C) 1.2 102 lb
D) 96. lb
E) 1.56 102 lb
Question 2A submarine rests on the sea bottom. The normal force exerted upon the sub by the sea-floor is equal to
A) the buoyant force less 1 atmosphere acting on the sub.
B) the weight of the sub plus the weight of the displaced water.
C) the weight of the sub.
D) the weight of the sub less the weight of the displaced water.
E) the weight of the displaced water.
Question 3The speed for a low circular orbit about the Earth is about
A) 1.7 104 km/s.
B) 7.6 km/s.
C) 2.1 km/s.
D) 2.5 104 km/s.
E) 17. km/s.
Question 4Compared to the wavelength of a 400 Hz sound, the wavelength of a 200 Hz sound in air is
A) four times as long.
B) twice as long.
C) the same.
D) one-half as long.
E) none of the above
Question 5What parameters determine the position of a galaxy's Galactic Habitable Zone?
A) only the amount of heavy elements in the disk
B) both the amount of heavy elements AND the amount of radiation from the center
C) only the temperature in the galactic disk
D) only the amount of harmful radiation from the center
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