Gravity — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. An astronaut weighs 120 pounds on Earth. About what would she weigh on the Moon?
A) About 20 pounds
B) About 60 pounds
C) About 100 pounds
D) About 720 pounds
120 divided by 6 equals 20 pounds, the Moon weight.
2. A rover that weighs 100 pounds on Earth would weigh about how much on Mars?
A) About 10 pounds
B) About 40 pounds
C) About 100 pounds
D) About 250 pounds
100 multiplied by 0.4 equals 40 pounds on Mars.
3. A 60-pound dog on Earth would weigh about how much on the Moon?
A) About 5 pounds
B) About 10 pounds
C) About 30 pounds
D) About 360 pounds
60 divided by 6 equals 10 pounds on the Moon.
4. Which place has the strongest gravity for a Grade 5 student to feel?
A) Earth's surface
B) Mars surface
C) Moon's surface
D) Open space far from any planet
Earth gravity is strongest at about 1.0, Mars is 0.4, Moon is 0.17, and deep space is near zero.
Part B: Fill in the Blank
Write the correct answer on each line.
1. If you weigh 90 pounds on Earth, you would weigh about 15 pounds on the Moon.
90 divided by 6 equals 15 pounds on the Moon.
2. A 50-pound dog on Earth would weigh about 20 pounds on Mars.
50 multiplied by 0.4 equals 20 pounds on Mars.
3. A spacecraft part that weighs 600 pounds on Earth weighs about 100 pounds on the Moon.
600 divided by 6 equals 100 pounds on the Moon.
4. If a robot weighs 250 pounds on Earth, it weighs about 100 pounds on Mars.
250 multiplied by 0.4 equals 100 pounds on Mars.
5. The mass of a 30-pound rock stays the same on every world, but on the Moon its weight is about 5 pounds.
30 divided by 6 equals 5 pounds, the Moon weight, while mass does not change.