Areal image is four times as far from a lens as is theobject.
what is the object distance, measured in focal lengths? the lens

1.25 focal lengths

Explanation:

The lens equation states that:

where

f is the focal length

p is the object distance

q is the image distance

In this problem, the image is 4 times as far from the lens as is the object: this means that

If we substitute this into the lens equation and we rearrange it, we get

so, the object distance measured in focal lengths is

1.25 focal lenghts

d) the number of neutrons plus the number of protons

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.