Weight Examples in Physics

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Weight.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Physics.

Concept Recap

The gravitational force acting on an object due to its mass, directed toward the center of a massive body.

How hard gravity pulls you toward the ground — it changes on different planets.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Weight is a force measured in Newtons — not the same as mass measured in kilograms.

Common stuck point: Scales measure weight (force), but display mass (kg). On the Moon, the scale would show less.

Sense of Study hint: When you see a weight problem, first identify the mass of the object in kilograms and the gravitational acceleration (use g = 9.8 m/s² on Earth). Then substitute into W = mg. Finally, remember that weight is a force measured in newtons, not kilograms.

Worked Examples

Example 1

easy
What is the weight of a 12 \text{ kg} object on Earth? Use g = 9.8 \text{ m/s}^2.

Solution

  1. 1
    Use the weight formula: W = mg, where m is mass and g = 9.8 \text{ m/s}^2.
  2. 2
    Identify the given values: m = 12 \text{ kg}, g = 9.8 \text{ m/s}^2.
  3. 3
    Substitute and calculate: W = 12 \times 9.8 = 117.6 \text{ N}

Answer

W = 117.6 \text{ N}
Weight is the gravitational force acting on an object, calculated as the product of mass and gravitational acceleration. It is measured in newtons.

Example 2

hard
A person weighs 686 \text{ N} on Earth (g = 9.8 \text{ m/s}^2). What would they weigh on Jupiter where g_J = 24.8 \text{ m/s}^2?

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

medium
An object weighs 196 \text{ N} on Earth. What is its mass? Use g = 9.8 \text{ m/s}^2.

Example 2

easy
A 15 \text{ kg} backpack is on Mars where g = 3.7 \text{ m/s}^2. What is its weight?
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Background Knowledge

These ideas may be useful before you work through the harder examples.

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