Mass vs. Weight

In order to calculate force, we must initially know the difference between mass and weight. Then we need to know how to calculate the force.

Mass: Mass is the of matter in an object. For example, the mass of a brick is greater than the mass of a feather because the brick contains more matter. The metric unit for mass is the kilogram (kg). Smaller masses are measured in grams (g). There are 1000 g in 1 kg.


Since mass is the amount of matter in a object, the object's mass will not change, as a result of gravity. For example, if you weigh 50 kg on Earth, your mass on the moon, where gravity is 1/6 Earth's gravity, is still 50 kg. This is because the amount of matter in your body has not changed, your weight has.

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Weight: Weight is the amount of force on an object due to gravity. The weight of an object is rarely the same as its mass. If you traveled to the moon, your weight would change because the force of gravity changes as well. The force of gravity on the Earth is about six times stronger than the force of gravity on the moon, therefore you would be six times lighter on the moon than you would be on Earth.


external image Astronaut.jpg


For more information about mass vs. weight, watch the video below.











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