Answer:
The power of the lens of an eye adjust or bends the light rays to provide an image on the retina depending on distance of the object.
Explanation:
The lens of an eye and the cornea work together in forming a real image in the retina that houses numerous receptors in the fovea and blind spot of the optic nerve.
Image will be formed in the retina when light rays converging most at the cornea upon entering and exiting the lens.The power of adjusting the eyes focal length is known as accommodation.
Human can produce a maximum mechanical power of 1/3 hp (horse-power).
Horse power is a unit of power, it equals 746 watt (watt is also a power unit, known to be equal to a joule per second)
So:
1 ph = 746 watt = 746 J/s
1/3 ph = 248.6 J/s
we're looking for the calories, so
1 joule = 0.239006 calories
So human produce a maximum mechanical power of:
248.6 J/s = 82.88 calories per second.
We're looking for the number of calories consumed in three hours, so:
82.88 cal/s = 82.88 cal/s * 3600 s * 3 = 895200 calories = 895.2 kilocalories (food calories).
The number of food calories is 895.2 food calories
