Skip to content
Grade 6 Beginner About 15 min Version 1 Awaiting review Premium

Mass and weight on Earth, the Moon and beyond

Mass is the amount of matter in an object, measured in kilograms (kg) with a beam balance, which compares the object with standard masses. Weight is the force of gravity pulling on the object, measured in newtons (N) with a spring balance. On Earth, gravity pulls each kilogram with about 9.8 N. The Moon's gravity is about one sixth as strong, so things weigh less there, but their mass does not change. Weight = mass × gravitational field strength (W = m × g).

What you will learn

  • Distinguish mass from weight.
  • Use a beam balance to measure mass and a spring balance to measure weight.
  • Calculate weight using W = m × g.

Before you start

  • Know that gravity pulls objects towards the Earth.

Materials

  • A book, a water bottle, a bag of rice and a school bag

Equipment

  • Beam balance with standard masses
  • Spring balance marked in newtons

Procedure

  1. Weigh the bag of rice on Earth with both balances and record the readings.
  2. Take it to the Moon and weigh it again. Which reading changed?
  3. Weigh a second object on Earth.
  4. Try Mars and Jupiter.

How this simulation is simplified

  • Gravitational field strength: Earth 9.8 N/kg, Moon 1.6 N/kg, Mars 3.7 N/kg, Jupiter 24.8 N/kg (at the cloud tops).