What arrangement is not seen in rod shaped cells? coccus shaped cells?

The place you get your hair cut has two nearly parallel mirrors 6.00 m apart. as you sit in the chair, your head is 2.00 m from the nearer mirror. looking toward this mirror, you first see your face and then, farther away, the back of your head. (the mirrors need to be slightly nonparallel for you to be able to see the back of your head, but you can treat them as parallel in this problem.) how far away does the back of your head appear to be?

Could we see a galaxy that is 20 billion light-years away?

The electric field inside a battery generates an electric potential difference of 12v. the plates are seperated by a distance of 0.25m. what strength of the electric field?