How much air must be pushed downward at 40.0 m/s to keep an 830-kg helicopter aloft?
a. 20.8 kg/s
b. 203 kg/s
c. 33 200 kg/s
d. 208 kg/s
e. 193 kg/s
b
You might also like to view...
One advantage of using air as the working fluid in a solar collector is ________
a. that freezing will not be a problem b. that water heats up faster than air c. a smaller storage facility can be used d. that one needs hot water for showers
Which statement about the ecliptic is FALSE?
A) The Sun appears to move about a degree per day eastward long it. B) It is tilted 23.5 degrees with respect to the equator. C) The year is marked by the Sun's return to the same place along it. D) The Moon can never leave it, but moves twelve times faster than the Sun. E) The major planets stay close to it, but not always on it.
The earliest evidence of ancient life, blue-green algae, are
a. cyanobacteria. b. amber. c. foraminifera. d. coal.
How do we think the "hot Jupiters" around other stars were formed?
A) They formed as jovian planets close to the star in the same orbits that they are seen today. B) They formed as dense, rocky planets close to the star in the same orbits that they are seen today. C) They formed as jovian planets beyond the frost line and then migrated inward. D) Many planets were formed around the star but coalesced into a single planet close in. E) They spun off from the young star when it was rapidly rotating.