It would take you approximately an hour and 15 mins
Answer:
R=9.
C=(2,-2,0).
Explanation:
Lets try to find how 
can be written in the form of 
, since then its radius R and center of coordinates C=(a,b,c) would be easily recognizable.
Since we have the terms -4x and +4y, they seem to have come from the terms 
and 
, and we would need to take care of the extra +4 by substracting then. More explicitly:
, as we had originally with the x terms
, as we had originally with the y terms
Which means:
Or, putting all together:
So our radius is 9 and the center is (2,-2,0).
Answer:
correct answer is C
Explanation:
In this exercise, you are asked to complete the sentences so that the sentence makes sense.
1) in projectile launching, the only force that acts is gravity in the vertical direction, so the time of going up is EQUAL to the time of going down
correct answer C
2) when a body falls freely, the acceleration is the ratio of gravity, therefore if it starts from rest, its height is
y = v₀ t - ½ gt²
v₀ = 0
y = -1/2 g t²
so the position is not proportional to the square of the time
correct answer is C
Answer:
The average diameter of a single alveolus is 0.0222 cm.
Explanation:
Volume of the lung ,V= 1.9 L
Number of alveoli in a human lung = 
Volume of single alveoli =v
The alveoli are spherical.
Radius of an alveolus = r
Volume of the sphere = 
Diameter of the alveolus =d
d = 2r = 2 × 0.0111 cm = 0.0222 cm
The average diameter of a single alveolus is 0.0222 cm.
