Hawai'i Space Grant Consortium, Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, 1996

How Much Do You Weigh?
Purpose

To understand that weight is a measure of gravitational attraction and that this force is not the same on each planet.

Key Words

force

gravity

gravitational attraction

weight

mass



Materials

"New" Weight Chart

calculators

bathroom scale

Background
Gravity is a universal, natural force that attracts objects to each other. Gravity is the pull toward the center of an object; let's say, of a planet or a moon. When you weigh yourself, you are measuring the amount of gravitational attraction exerted on you by Earth. The Moon has a weaker gravitational attraction than Earth. In fact, the Moon's gravity is only 1/6 of Earth's gravity. So, you would weigh less on the Moon. How much would you weigh on the Moon and on the other planets?

Procedure

1.
Write your weight (or an estimate) here:



2.
For a different planet, multiply your weight by the number given in the "New" Weight Chart.



Example for the Moon - for a person weighing 60 pounds on Earth:
60 x 1/6 = 10
A 60 pound person would weigh 10 pounds on the Moon!
This example uses weight in pounds, but you can do this activity using any unit you wish.

3.
Follow the example and fill in the blanks in the "New" Weight Chart. Show your work.






"New" Weight Chart

PlanetMultiply your Earth weight by:Your "new" weight
Mercury0.4
Venus0.9
Earth1
Moon0.17
Mars0.4
Jupiter2.5
Saturn1.1
Uranus0.8
Neptune1.2
Pluto0.01
Sun28

Extensions
A nice on-line activity to calculate your weight on the planets and moons is available at The Exploratorium.
Another on-line activity with a fill-in table is available at StarChild, from NASA Goddard Space Flight Center.

Question: Where do the multiplication factors come from?
Answer: Each number is the gravitational attraction, relative to Earth's, of each planet in our solar system. Remember, gravity is the force of attraction between two objects and is influenced by the mass of the two objects and the distance between the two objects. You can use any unit you wish for your weight.

The "New" Weight Chart can be built as a spreadsheet; thus adding database-computer skills into the activity. This great idea was shared by Mary L. Wyatt, University of Michigan-Dearborn, School of Education.   [7 DEC 1999]


Return to Planetary Properties Activity Index.

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