Satellites: orbital speed and period

Answer Key - Grade 11 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   Earth's GM is 398,600 km³/s² and its radius is 6371 km. For a model satellite 400 km up, inside the ISS's range, what is the period in minutes, to the nearest tenth, Ari?

   92.4 min
2. 2.

   Earth's GM is 398,600 km³/s² and its radius is 6371 km. For a model satellite in a high test orbit 2000 km up, what is the period in minutes, to the nearest tenth, Esme?

   127 min

3. Read this first

   Circular orbits around Earth, worked out from Earth's GM (computed from NASA's GM)

   Height (km)	Speed (km/s)	Period (min)
   600	7.56	96.5
   1500	7.12	115.8
   10000	4.93	347.4
   35786	3.07	1435.7

4. 3.

   Using the table, how do speed and period change as the height goes up, Jun?

   • Speed falls and the period grows
   • Both stay about the same
   • Speed rises and the period grows
5. 4.

   Using the table, at which height does one orbit take about one day, Kira?

   • 600 km
   • 10,000 km
   • 35,786 km
6. 5.

   Using the table, about how many times longer is the period at 10,000 km than at 600 km, Luz?

   • About 16.7 times
   • About 2 times
   • About 3.6 times
7. 6.

   Noah says the Moon moves faster than the ISS because its orbit is much bigger. Agree or disagree?

   • Agree: the Moon is heavier
   • Agree: bigger orbits need higher speeds
   • Disagree: the ISS is about 7.5 times as fast
8. 7.

   Pia says there is no gravity at the ISS's height. Agree or disagree?

   • Agree: gravity stops above the air
   • Disagree: g there is still about 8.5–8.8 N/kg
   • Agree: things float there, so gravity there is zero
9. 8.

   A model satellite moves from an orbit 1000 km up to one 2000 km up. How do its speed and period change, Ren?

   • Both grow
   • Speed falls; period grows
   • Speed rises; period falls
10. 9.

    Why does draw a line from thin air make the ISS's orbit shrink over time, Tala?

    • Drag takes away energy, so it sinks lower
    • Drag adds energy
    • Drag pushes it outward
11. 10.

    The ISS takes about 92 minutes per orbit at 370 km and 94 at 460 km. Why is its period given as a range, Zee?

    • Clocks on the ISS run unevenly
    • Its height changes, so its period changes too
    • The ISS keeps changing its mass