What makes the pull of gravity stronger or weaker

Grade 6 Science Worksheet

Circle the best answer.

1. Read this first

   Table (NASA Planetary Fact Sheet), NASA values, with columns Planet, Mass (10²⁴ kg), Diameter (km) and Gravity (m/s²)

   Earth, mass 5.97 (×10²⁴ kg), diameter 12,756 km, gravity 9.8 m/s²; Saturn, mass 568 (×10²⁴ kg), diameter 120,536 km, gravity 9.0 m/s².

2. 1.

   Saturn has about 95 times Earth's mass, yet its gravity at the cloud tops is a little less than Earth's. Why, by Bo's reasoning?

   • Gas planets have no gravity
   • Mass does not affect gravity
   • Saturn is so wide that its cloud tops are far from its center
   • Saturn should have about 95 times Earth's gravity

3. Table (NASA Planetary Fact Sheet), NASA values, with columns Planet, Mass (10²⁴ kg), Diameter (km) and Gravity (m/s²)

   Mercury, mass 0.330 (×10²⁴ kg), diameter 4,879 km, gravity 3.7 m/s²; Mars, mass 0.642 (×10²⁴ kg), diameter 6,792 km, gravity 3.7 m/s².

4. 2.

   Mercury and Mars both have surface gravity of 3.7 m/s², but Mars has about twice Mercury's mass. How can that be, says Esme?

   • Mars is wider, so its surface is farther from its center
   • Mercury is closer to the Sun, so it gains gravity
   • Mass makes no difference to gravity
   • The two planets must have the same mass
5. 3.

   Earth, gravity 9.8 m/s², diameter 12,756 km; Jupiter, gravity 23.1 m/s², diameter 142,984 km. Jupiter has about 318 times Earth's mass. Using the NASA table, about how many times Earth's gravity does it have at its cloud tops, by Jun's math?

   • About the same as Earth's
   • Less than Earth's
   • About 2.4 times
   • About 318 times, to match its mass

6. Table (NASA Planetary Fact Sheet), with columns World and Gravity, m/s², surface gravity in m/s²

   Earth 9.8; Moon 1.6; Mars 3.7.

7. 4.

   Kira's backpack weighs 12 lb on Earth. Using the NASA table, about how much would it weigh on the Moon?

   • About 2 lb
   • About 72 lb, six times more
   • About 12 lb, the same as on Earth
   • 0 lb, since the Moon has no gravity
8. 5.

   About how much would the same 12 lb backpack weigh on Mars, using the NASA table, by Luz's math?

   • About 32 lb
   • About 12 lb, since mass doesn't change
   • 0 lb, since Mars is so far from Earth
   • About 4.5 lb
9. 6.

   NASA's Curiosity rover has a mass of about 900 kg. On Mars, what is its mass, by Milo's reasoning?

   • About 340 kg, since Mars's gravity is weaker
   • 0 kg, since it is out in space
   • More, because of the red dust
   • Still about 900 kg

10. Use this

    Drawing, not to scale:

11. 7.

    The International Space Station orbits about 400 km above Earth. Why do the astronauts float inside, by Noah's reading?

    • There is no gravity in space
    • The station is too far for Earth to pull it
    • Their mass drops to zero in orbit
    • They and the station are falling around Earth together
12. 8.

    About how strong is Earth's gravity at the space station's height, compared with on the ground? Pia checks NASA.

    • About 1% as strong
    • About 90% as strong
    • Zero
    • Stronger than on the ground
13. 9.

    The station above Earth with its sideways motion arrow crossed out and a pull arrow toward Earth. If the space station somehow stopped moving sideways, what would Earth's gravity do to it, as Ren predicts?

    • Nothing; there is no gravity up there
    • Pull it down toward Earth
    • Push it farther away
    • Hold it perfectly still in place

14. Use this

    Drawing of a sealed chamber labeled "no air" with a bowling ball and a tennis ball held at the same height.

15. 10.

    In a room with all the air pumped out, a bowling ball and a tennis ball are dropped together. How do they land, by Ari's prediction?

    • Neither falls, since there is no air
    • The tennis ball first, since it is lighter
    • The bowling ball first, since it is heavier
    • At the same time