Answers to Physics Module Questions - Module #9
  1. If the mass of the sun and the earth are both tripled, and the distance between them is also tripled, the force between them will be
    1. doubled
    2. halved
    3. tripled
    4. one third
    5. the same
    6. nine times
    7. one ninth
  2. You don’t see tides in your swimming pool. This is because
    1. your contact lenses are missing
    2. magnetic forces hold the water down
    3. the pool is too shallow for tides
    4. the pool is too deep for tides
    5. the tides happen at night when you are asleep
    6. all parts of the pool are at about the same distance to the moon
  3. The distance between the earth and the moon is reduced to one third. The gravitational force between them becomes
    1. 3 times bigger
    2. 3 times smaller
    3. 9 times bigger
    4. 9 times smaller
    5. stays the same
  4. What keeps the earth from falling into the sun?
    1. strings hold the earth up
    2. gravity holds the earth up
    3. the earth's tangential speed
    4. smoke and mirrors
    5. the sun's gravity is zero where the earth is
  5. What is a black hole ?
    1. a hole in your dry-wall
    2. space with no stars
    3. space with no light
    4. space with no mass
    5. a space with mass so highly concentrated that even light cant escape the resulting gravity

PHYSICS WORLD .ORG
Module-9 Questions | Home