A person runs up a long flight of stairs in 10 seconds. If the person's weight is 600 N and the vertical height of the stairs is 20 meters, what is the person's power output?
1,200 W
You might also like to view...
Radioactive Decay: What happens to the half-life of a radioactive substance as it decays?
A. It remains constant. B. It increases. C. It decreases at a constant rate. D. It decreases at an exponential rate.
The angle that an incident light ray makes with the surface normal is
A. smaller than the angle that the reflected ray makes with the normal B. the same size as the angle that the reflected ray makes with the normal C. greater than the angle that the reflected ray makes with the normal
The escape speed at the event horizon of a black hole is c, 300,000 km/sec
Indicate whether the statement is true or false
Suppose a scientist holds a press conference at which he claims that 10% of the matter in the Milky Way is in the form of dust grains. Does his claim seem reasonable? Why or why not?
A) It is reasonable because we already know that interstellar dust obscures our view through the disk of the galaxy. B) The 10% figure is too high because there are not enough heavy elements to make that much dust. C) It seems reasonable as long as we assume that red giant stars—which produce dust grains in their stellar winds—are more common than we thought. D) The 10% figure is too low because most of the mass of the galaxy is in the form of interstellar dust.