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?

   • Mass does not affect gravity
   • Saturn should have about 95 times Earth's gravity
   • Saturn is so wide that its cloud tops are far from its center
   • Gas planets have no 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
   • The two planets must have the same mass
   • Mercury is closer to the Sun, so it gains gravity
   • Mass makes no difference to gravity
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?

   • Less than Earth's
   • About the same as Earth's
   • About 318 times, to match its mass
   • About 2.4 times
6. 4.

   Earth 9.8; Moon 1.6; Mars 3.7. Kira's backpack weighs 12 lb on Earth. Using the NASA table, about how much would it weigh on the Moon?

   • About 72 lb, six times more
   • 0 lb, since the Moon has no gravity
   • About 2 lb
   • About 12 lb, the same as on Earth
7. 5.

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

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

8. Use this

   Drawing, not to scale:

9. 6.

   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
   • They and the station are falling around Earth together
   • Their mass drops to zero in orbit
   • The station is too far for Earth to pull it
10. 7.

    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
    • Stronger than on the ground
    • Zero
11. 8.

    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?

    • Hold it perfectly still in place
    • Pull it down toward Earth
    • Nothing; there is no gravity up there
    • Push it farther away
12. 9.

    On the airless Moon in 1971, Apollo 15 astronaut David Scott dropped a hammer and a feather together. What happened, as Tala reads from NASA?

    • The feather floated away
    • They landed at the same time
    • The hammer landed first, since it is heavier
    • Neither fell, since the Moon has no gravity

13. Use this

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

14. 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?

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