Gravity on other worlds

Answer Key - Grade 11 Science Worksheet - Challenge Me

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

1. 1.

   Mercury: mass 0.33 × 10²⁴ kg, diameter 4879 km. Earth: 5.97 × 10²⁴ kg, 12,756 km, g = 9.8 m/s². To the nearest tenth, what is g on Mercury, Bo?

   3.7 m/s²
2. 2.

   The Moon: mass 0.073 × 10²⁴ kg, diameter 3475 km. Earth: 5.97 × 10²⁴ kg, 12,756 km, g = 9.8 m/s². To the nearest tenth, what is g on the Moon, Esme?

   1.6 m/s²

3. Read this first

   Four planets (NASA planetary fact sheet)

   World	Mass (10²⁴ kg)	Diameter (km)	g (m/s²)
   Earth	5.97	12756	9.8
   Venus	4.87	12104	8.9
   Mars	0.642	6792	3.7
   Jupiter	1898	142984	23.1

4. 3.

   Using the table, Jupiter has about 318 times Earth's mass. Why is its g only about 2.4 times Earth's, Jun?

   • Jupiter spins too slowly to hold things
   • Its radius is about 11 times Earth's
   • Its g should be 318 times; the table is wrong
5. 4.

   Using the table, Venus has about 82% of Earth's mass and 95% of its diameter. How does its g compare with Earth's, Kira?

   • More than Earth's, since Venus is warmer
   • A little less: 8.9 against 9.8 m/s²
   • About 82% of Earth's, like its mass
6. 5.

   Milo says a rover loses mass when it lands on the Moon. Agree or disagree?

   • Disagree: only its weight changes
   • Agree: the Moon pulls some of its mass away
   • Agree: it weighs less, so it has less mass
7. 6.

   Noah says a planet with twice Earth's mass must have twice Earth's surface gravity. Agree or disagree?

   • Disagree: it also depends on the radius
   • Agree: radius has no effect on g
   • Agree: surface gravity depends on mass alone
8. 7.

   Pia says a box weighing 37 N on Mars has a mass of 37 kg. Agree or disagree?

   • Agree: weight and mass are the same number
   • Disagree: 37 ÷ 3.7 = 10 kg
   • Agree: on Mars, newtons and kilograms match
9. 8.

   A model world has 4 times Earth's mass and 2 times its radius. What is its surface gravity, Ren?

   • 19.6 m/s²
   • 39.2 m/s²
   • 9.8 m/s², the same as Earth's
10. 9.

    A model world is made of the same rock as Earth, packed just as tightly, with half Earth's radius. How does its g compare, Tala?

    • One-eighth of Earth's
    • 4 times Earth's
    • Half of Earth's
11. 10.

    A model world has 9 times Earth's mass. What radius gives it the same surface gravity as Earth, Zee?

    • 81 times Earth's radius
    • 9 times Earth's radius
    • 3 times Earth's radius