The internal energy of a material is determined by
its temperature
the kinetic energy of its molecules
the potential energy of its molecules
the combined amount of kinetic and potential energy of its molecules

i believe i could be wrong but i think its kinetic energy.

its the combined amount of kinetic and energy molecules. if wrong then temperature for backup

i think the answer is a, hope this is right, that would be my best guess.

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)