<span>Astronomy is a natural science that studies celestial objects and phenomena. More generally, all astronomical phenomena that originate outside Earth's atmosphere are within the purview of astronomy.
Therefore, the correct answer to the question "Astronomy can best be described as a/an" is "study of objects beyond the Earth's atmosphere."</span>
The correct answer is true
(a) +9.30 kg m/s
The impulse exerted on an object is equal to its change in momentum:

where
m is the mass of the object
is the change in velocity of the object, with
v = final velocity
u = initial velocity
For the volleyball in this problem:
m = 0.272 kg
u = -12.6 m/s
v = +21.6 m/s
So the impulse is

(b) 155 N
The impulse can also be rewritten as

where
F is the force exerted on the volleyball (which is equal and opposite to the force exerted by the volleyball on the fist of the player, according to Newton's third law)
is the duration of the collision
In this situation, we have

So we can re-arrange the equation to find the magnitude of the average force:

Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering- resistant rocks, such as quartzite, given the right conditions.
Answer:
False
Explanation:
It is a common misunderstanding that objects in space have no weight. If that were true, they would just float away from the Earth, the Sun and the other planets. Objects in low Earth orbit experience about 90% of the weight that they feel on the surface of the Earth.