I think it is building and managing of irrigation systems
Answer:
Gravity ( gravity , weight, traction force) is the force acting on any body on or near the surface of the celestial body directed at its center. Gravity, that is, the force with which the earth , moon , planets, and other celestial bodies or their systems act on other bodies, is theoretically exercised at any distance, but is practically examined on the surface of these bodies as well as at short distances.
Answer:
0.6375 m/s
Explanation:
Let x be the distance of the man from the building
from the figure attached
initially the value of x=12
Given:

where the negative sign depicts that the distance of the man from the building is decreasing.
Now, Let The length of the shadow be = y
we have to calculate
when x=4
from the similar triangles
we have,
or

Differentiating with respect to time 't' we get

or

Now for x = 4, and
we have,

or

<u>here, the negative sign depicts the decrease in length and in the question it is asked the decreasing rate thus, the answer is </u><u>0.6375m/s</u>
Answer:
b
Explanation:
radiation can treat tumors.