Suppose engineers built a rotating space station similar to Space Station V from the film 2011: A Space Odyssey, but with multiple concentric rings where astronauts can live.

    ____________
   /  ____c___  \
  /  /  __b_  \  \
 /  /  /  a \  \  \
/  /  /      \  \  \
\  \  \      /  /  /
 \  \  \____/  /  /
  \  \________/  /
   \____________/

Ring a is 10 meters from the center, ring b is 20 meters from the center, and ring c is 30 meters from the center.

• If the station is set to rotate at a speed where the gravity within ring b is identical to Earth's gravity, will the gravity in rings a and c be significantly stronger or weaker?
• If the concentric rings could rotate freely, would rings a and c need to rotate faster or slower than ring b to ensure that the gravity at each ring had identical strength?