CurriculumGrade 8Science

Gravity Depends on Mass

Aligned to MS-PS2-4 — Next Generation Science Standards.

What this lesson teaches

Gravity is an attractive force between any two objects that have mass, and the force is stronger when the masses are larger. It is always a pull, never a push.

Worked example

The Sun's enormous mass pulls Earth into orbit, and Earth pulls back on the Sun. Because the Moon has far less mass than Earth, its surface gravity is only about one-sixth as strong.

Practice questions

  1. Observe planetary data and describe how a planet's mass relates to its gravitational pull.
  2. Construct an argument, using evidence, that gravity is always attractive and never repulsive.
  3. Explain why you would weigh less on the Moon than on Earth even though your mass is unchanged.

Watch the lesson

Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.

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En español

La Gravedad Depende de la Masa

La gravedad es una fuerza de atracción entre dos objetos cualesquiera que tengan masa, y la fuerza es más intensa cuando las masas son mayores. Siempre es un jalón, nunca un empujón.

Ejemplo: La enorme masa del Sol jala a la Tierra en su órbita, y la Tierra jala de regreso al Sol. Como la Luna tiene mucha menos masa que la Tierra, su gravedad en la superficie es solo cerca de un sexto de intensa.

More Motion & Stability: Forces & Interactions lessons

Newton's Third Law in CollisionsMS-PS2-1Forces, Mass & Changing MotionMS-PS2-2What Affects Electric & Magnetic ForcesMS-PS2-3Fields Act at a DistanceMS-PS2-5

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