Ekapluto is an unknown planet that has two moons in circular orbits. The table summarizes the hypothetical data about the moons. (G = 6.67 × 10-11 N ? m2/kg2)
Mass Radius Orbital radius Orbital period
Moon A 4.0 × 1020 kg 2.0 × 108 m 4.0 × 106 s
Moon B 1.5 × 1020 kg 2.0 × 105 m 3.0 × 108 m
The mass of Ekapluto is closest to
A) 1.0 × 1022 kg.
B) 3.0 × 1022 kg.
C) 1.0 × 1023 kg.
D) 3.0 × 1023 kg.
E) 1.0 × 1024 kg.
Answer: D
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An object is placed in front of a convex mirror at a distance larger than twice the focal length of the mirror. The image will appear
A) in front of the mirror. B) inverted and reduced. C) inverted and enlarged. D) upright and reduced. E) upright and enlarged.
The minimum or no magnetic force on a moving electron occurs for motion
A) parallel to the magnetic field. B) perpendicular to the magnetic field. C) at non-right angles to the magnetic field direction.
A string fixed at both ends is vibrating in one of its harmonics. If we now increase only the frequency at which the string is vibrating, which of the following characteristics do we also increase? (There could be more than one correct choice.)
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