The apparent weight of a 75 kg astronaut in orbit, who would be experiencing weightlessness, is 0 N. This is because in orbit astronauts are in free fall, meaning there are no contact forces acting on them to provide a sensation of weight.
The question asks about the apparent weight of a 75 kg astronaut. Apparent weight refers to the weight an object seems to have when acted upon by forces other than gravity, such as the force of a scale against a person's feet. In circumstances where only gravity is acting on the person, such as in free fall or orbit, the apparent weight would be zero because the person would not feel any contact forces pushing against them, giving them the sensation of weightlessness.
In the case of an astronaut in orbit, as indicated by reference to astronauts being apparently weightless, the correct answer is B. 0 N, because the astronaut would be in free fall around the Earth, experiencing weightlessness. Although the mass of the astronaut remains constant at 75 kg, the apparent weight changes depending on the forces acting on the astronaut. Therefore, with no contact force to provide a sensation of weight, his apparent weight would be zero.
The astronaut's apparent weight in orbit, where he experiences weightlessness, is 0 N.