Gravity is the pull
that every object exerts on other objects. The more massive an object,
the greater the gravitational pull it can exert on another object. The
further the distance between two objects, however, the smaller the gravitational
pull. It is gravity that holds planets and stars together and gives them
their nearly spherical shape, and it is the gravitational pull of the
Earth that keeps things – such as ourselves – from floating
off into space. It is the Sun’s gravitational attraction that holds
the planets in their orbits.
When we weigh an object, we
are measuring the Earth’s gravitational pull on it. On a different
planet, the same object could have a different weight, because the planet’s
mass and radius might be different than the Earth’s. On Mercury,
the gravitational force on an object – its weight – would
be only 37% as large as on Earth. For example, if you weighed 600 N (135
lb) on Earth you would weigh only 220 N (50 lb) on Mercury.
| Odd
but true: The Sun is far more massive than any of the planets
in our Solar System. In fact, if you weighed 600 N on Earth, you
would be about 28 times as heavy – about 168,000 N, or 37,500
lb – on the surface of the Sun! To determine how much you
would weigh on another planet, use the CERES Solar System Weight
Calculator by clicking on the link below. |
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