If a nearsighted person has a far point df that is 3.50m from the eye, what is the focal length f1 of the contact lenses that th
e person would need to see an object at infinity clearly?
If a farsighted person has a near point that is 0.600m from the eye, what is the focal length f2 of the contact lenses that the person would need to be able to read a book held at 0.350m from the person's eyes?
If a farsighted person has a near point that is 0.600m from the eye, what is the focal length f2 of the contact lenses that the person would need to be able to read a book held at 0.350m from the person's eyes?
1 answer:
Answer:
f1= -350cm or -3.5m
f2= 22.1cm or 0.221m
Explanation:
A person is nearsighted when the person's far point is less than infinity. A diverging lens is normally used to correct this eye defect. A diverging lens has a negative focal length as seen in the solution attached.
Farsightedness is when a person's near point is farther than 25cm. This eye defect is corrected using a converging lens. The focal length of a converging lens is positive. This is evident in the solution attached. The near point is also referred to as the least distance of distinct vision.
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Explanation:
The given data is as follows.
Inner wheel Radius = 20 m,
Distance between left and right wheel = 1.5m,
Let us assume speed of drive shaft is N rpm.
Formula to calculate angular velocity is as follows.
Angular velocity of automobile = w =
where, V = linear velocity of automobile m/min,
R = turning radius from automobile center in meter
In the given case, angular velocity remains same for inner and outer wheel but there is change in linear velocity of inner wheel and outer wheel.
Now, we assume that
u = linear velocity of inner wheel
and, u' = linear velocity of outer wheel.
Formula for angular velocity of inner wheel w = ,
Formula for angular velocity of outer wheel w =
Now, for inner wheels
w =
=
u =
=
If radius of wheel is r it will cover distance in one min.
Since, velocity of wheel is u it will cover distance u in unit time(min)
Thus, u = =
Now, rotation per minute of inner wheel is calculated as follows.
n =
= (since 2d = 1.5m given, d = 0.75m),
=
So, rotation per minute of outer wheel; n' =
=
=