Answer:
The near point of an eye with power of +2 dopters, u' = - 50 cm
Given:
Power of a contact lens, P = +2.0 diopters
Solution:
To calculate the near point, we need to find the focal length of the lens which is given by:
Power, P = 
where
f = focal length
Thus
f = 
f = 
= + 0.5 m
The near point of the eye is the point distant such that the image formed at this point can be seen clearly by the eye.
Now, by using lens maker formula:
where
u = object distance = 25 cm = 0.25 m = near point of a normal eye
u' = image distance
Now,
Solving the above eqn, we get:
u' = - 0.5 m = - 50 cm
Explanation:
Uniform velocity is when an object goes an equal amount of space in an equal amount of time whereas non uniform velocity is when the object covers an unequal amount of distance in an equal amount of time.
Answer: 3rd option
Explanation: Since it has less mass and same force as other object it will have higher acceleration
While rotating around Earth the Moon also rotates around it's axis. These two rotations have almost same duration (27.3 and 27 days respectively). This is the reason why we always see the same side of Moon.
The dark part of a Moon is the part where there is night on the Moon, meaning there is no sunlight visible. This dark part depends on the Moon's position relative to Earth and Sun. The change in size is due to part of Moon-day. Dark part of Moon has night, bright part has day and the boundary has either sunrise or sunset.
