An astronaut on the moon pushes with her left hand on a small rock and with her right hand on a large rock. each hand pushes with a force of 15 n. the small rock has mass 2 kg and the large rock has mass 8 kg. what forces do the rocks exert on the astronaut?

the small rock exerts a pushing force of 20 n; the large rock exerts a pushing force of 78 n.

the small rock exerts a pushing force of 3 n; the large rock exerts a pushing force of 12 n.

each rock exerts a pushing force of 7.5 n.

each rock exerts a pushing force of 15 n.

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

People with normal vision cannot focus their eyes underwater if they aren't wearing a face mask or goggles and there is water in contact with their eyes. in a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina.with the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 2.05cm in front of the eye.)

Which is not true of alpha radiation? o a. it increases the number of protons. o b. it has a positive charge. o c. it causes transmutation. o d. it is heaviest of the three types