college physics

posted by .

Although astronauts appear weightless, they are not. They only appear weightless because they are in free fall. If a 79 kg astronaut is orbiting Earth with an orbital radius of 5.31×107 m, determine how much the astronaut would weigh. Earth's mass is 5.974 1024 kg.

  • college physics -

    Your teacher is misleading you greatly. Be careful. I am wondering if you actually have a physics major teacher.

    I will solve this question: If a 79 kg astronaut is orbiting Earth with an orbital radius of 5.31×107 m, determine how much the astronaut would weigh ON EARTH. Earth's mass is 5.974 1024 kg.

    a) On Earth, the person weights 79*9.8 Newtons.
    Now for this question: If a 79 kg astronaut is orbiting Earth with an orbital radius of 5.31×107 m, determine how much the astronaut would weigh in orbit. Earth's mass is 5.974 1024 kg.

    Answer: zero, the astronaut is in free fall.

    I suspect your teacher has something else in mind, but frankly, I have no idea. If you get many of these, I would drop the class, and get a qualified teacher. Physics is an important subject.

    In orbit, there are two forces working: gravity, and centripetal force. To be weightless, those two are equal. Perhaps your teacher wants you to ignore centripetal force, and just figure the gravity force at that orbital radius. I just don't know.

  • college physics -

    Hmm. I thought gravity provided the centripetal force. The object wants to fly off at a tangent, but gravity keeps bending the trajectory.

    Is there another force besides gravity act work?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    Whenever two Apollo astronauts were on the surface of the Moon, a third astronaut orbited the Moon. Assume the orbit to be circular and 400 km above the surface of the Moon. At this altitude, the free-fall acceleration is 1.11 m/s2. …
  2. physics

    You have probably seen films of astronauts floating weightless in orbiting satellites. People often get the idea that the astronauts are weightless because they are so far from the gravity of the earth. Let us see if that explanation …
  3. Physics

    You have probably seen films of astronauts floating weightless in orbiting satellites. People often get the idea that the astronauts are weightless because they are so far from the gravity of the earth. Let us see if that explanation …
  4. Physics

    Suppose a space capsule with an astronaut inside is launched from the top of a tower at some angle above the horizontal. a)While the capsule is in free fall, what are the acceleration of the astronaut and the capsule?
  5. physics

    Whenever two Apollo astronauts were on the surface of the Moon, a third astronaut orbited the Moon. Assume the orbit to be circular and 720 km above the surface of the Moon, where the acceleration due to gravity is 0.839 m/s2. The …
  6. physics

    Using Newton's Law of Universal Gravitation, compare the weight of a 68.1 kg astronaut on the surface of the earth to the gravitational pull of the Earth on the same astronaut when she is on the International Space Station. Constants: …
  7. physics

    Using Newton's Law of Universal Gravitation, compare the weight of a 68.1 kg astronaut on the surface of the earth to the gravitational pull of the Earth on the same astronaut when she is on the International Space Station. Constants: …
  8. Physics

    If astronauts could travel at v=0.89c, we on Earth would say it takes (4.20/0.890)=4.72 years to reach Alpha Centauri, 4.20 light years away. The astronaut would disagree. (a) How much time passes on the astronaut's clocks?
  9. Physics

    You are explaining why astronauts feel weightless while orbiting in the space shuttle. Your friends respond that they thought gravity was just a lot weaker up there. Convince them and yourself that it isn't so by calculating the acceleration …
  10. Physics 20

    Astronauts in orbit appear to be 'weightless'.Suppose an astronaut with a mass of 154 KG including gear is in orbit in the space shuttle, a distance of 222 km above the Earth;s surface.Taking the Earth's radius to be 6371km, and its …

More Similar Questions