What is a standard candle?
A) an object for which we are likely to know the true luminosity
B) an object for which we can easily measure the apparent brightness
C) a class of objects in astronomy that all have exactly the same luminosity
D) any star for which we know the exact apparent brightness
E) a long, tapered candle that lights easily
A
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What is a "wormhole"?
A) a hypothetical connection through hyperspace between two points in the universe B) an observationally confirmed feature of the universe that allows interstellar travel and time travel C) another name for the shortest path between two points D) the opposite of a black hole; it ejects mass and energy out of it and nothing can enter
Hydrogen and oxygen molecules in a sample of gas have the same temperature. This means the hydrogen molecules, on average, have the same
A) speed and the same kinetic energy. B) speed, but more kinetic energy. C) speed, but less kinetic energy. D) kinetic energy, but more speed. E) kinetic energy, but less speed.
The first atomic explosion released approximately 1.0 × 1014 J of energy. How much matter had to be changed into energy to produce this yield?
A) 1.1 g B) 23 g C) 13 g D) 0.45 kg E) 1.1 kg
A car accelerates from rest to a speed of 19.0 m/s in 6.00 seconds. If the car weighs 16,000 N, what average power must the motor produce to cause this acceleration? Use g = 10 m/s2
A) 128 kW B) 15.0 kW C) 49.1 kW D) 219 kW E) 393 kW