2 thing it is used for are commonly like wind turbines and water turbines.
Answer:
32.6mm
Explanation:
Using area of a sphere(bulb) = 4πr²
So A is proportional to radius²
So the Energy will be proportional to r²
But 120/80 = 1.5 is the energy factor so
Using
1.5/d² = 1/r²
1.5/40²= 1/r^2
r = √( 40²/ 1.5)
r = 32.6m

Actually Welcome to the Concept of the Optical Devices.
Now basically here the devices that can spread light over apart are the CONCAVE LENS and Convex mirror.
so the Answer is
C. B and D
Answer:
Acceleration stress, physiological changes that occur in the human body in motion as a result of rapid increase of speed. ... A force of 3 g, for example, is equivalent to an acceleration three times that of a body falling near Earth.