On july 15, 2004, nasa launched the aura spacecraft to study the earth's climate and atmosphere. this satellite was injected into an orbit 705 km above the earth's surface, and we shall assume a circular orbit.
(a) how many hours does it take this satellite to make one orbit?
h
(b) how fast (in km/s) is the aura spacecraft moving?
km/s

Find the volume of the ellipsoid x^2+y^2+5z^2=36.

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

Apassenger walks toward the rear of a moving train. describe her motion as seen from a reference point on the train. then describe it from a reference point on the ground