<h3>Concave or diverging lens is needed correct the vision of a nearsighted person whose far point is 30.0 cm</h3>
<em><u>Solution:</u></em>
Nearsighted person will not be able to see the distant objects clearly
Now, we want the near sighted person to see the distant objects clearly
<em><u>The lens equation is given as:</u></em>

For distant vision, 

The image of 30 cm from eye will be 28.5 cm to left of spectacle lens
Therefore,

From lens equation,

The negative power -3.51 D denotes that a concave or diverging lens is needed
Answer:
Since incident wave and its reflected part in opposite phase superimpose on each other
So correct answer will be
Option B
Explanation:
Here we know that the wave reflection is done by rigid boundary
So when wave is reflected by the boundary then its phase is reversed by 180 degree
so the reflected wave is in reverse phase from the boundary
so we can superimpose the reflected part with incident wave to dine the resultant wave
So the phenomenon is given as follow
Their cognitive skills and their ability to learn
Answer:
Read below!
Explanation:
You can watch the sun wheel across the sky during the day, and the stars at night. Focus a telescope on any star besides the north star--especially southern stars--and you can watch them drift across your field of view.
An alternative explanation is that all the stars are painted on (or holes in) some canopy that rotates around the earth. This explanation does not account for the motion of the "wanderers," or planets, as the Greeks called them, or for the path of the moon among the stars.
As we know the stars are massive bodies of significant and varying distance to the earth, the notion they all swing around us in unison seems highly implausible
Answer:
20 Hz, 20000 Hz
0.0166 m, 16.6 m
Explanation:
The minimum frequency that a human ear can hear is 20 Hz
The maximum frequency that a human ear can hear is 20000 Hz.
v = Velocity of sound = 332 m/s
Wavelength is given by

The longest wavelength that can be heard by the human ear is 16.6 m

The shortest wavelength that can be heard by the human ear is 0.0166 m.