Answer:
1.0 dioptres
Explanation:
Farsightedness is an eye defect in which a person can see far objects clearly but not near objects. That implies that the patients' near point is farther than 25cm which is the normal least distance of distinct vision.
Farsightedness results from the eyeball being too long or the crystalline lens not being sufficiently converging.
Carol is farsighted with a near point of about a meter (100cm). We desire to make a lens to enable her near point be reduced to about 50cm. The focal length and power of this lens is calculated in the image attached.
The power of a lens is the inverse of its focal length in meters hence the 100 in the formula for power of the lens.
Answer:
Explanation:
A charge located at a point will experience a zero electrostatic force if the resultant electric field on it due to any other charge(s) is zero.
is located at the origin. The net force on it will only be zero if the resultant electric field intensity due to 
and 
at the origin is equal to zero. Therefore we can perform this solution without necessarily needing the value of .
Let the electric field intensity due to be +
and that due to be -
since the charge is negative. Hence at the origin;
From equation (1) above, we obtain the following;
From Coulomb's law the following relationship holds;
where 
is the distance of from the origin, 
is the distance of from the origin and k is the electrostatic constant.
It therefore means that from equation (2) we can write the following;
k can cancel out from both side of equation (3), so that we finally obtain the following;
Given;
Substituting these values into equation (4); we obtain the following;
I think the answer should be D.<span>It reduces the amount of thermal energy that is transferred from outside to inside the container. </span>
B. The Earth radiates an amount of energy into space equal to the amount it receives.
Part of the solar energy is reflected by the Earth into space, this is known as albedo. The other part of the energy radiated by the Earth in the form of infrared radiation, is absorbed by the greenhouse gases, which cause most of this infrared radiation to be emitted into space. Therefore, the net flow of energy is zero.
Answer:
a) the three longest wavelengths = 4.8m, 2.4m, 1.6m
b) what is the frequency of the third-longest wavelength = 75Hz
Explanation:
The steps and appropriate formula and substitution is as shown in the attached file.
