Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Mass () is the measure of the amount of matter in an object. It is a scalar quantity and remains constant regardless of where the object is in the universe. The SI unit for mass is the kilogram ().
Weight () is the force of gravity acting on an object. Because it is a force, it is measured in Newtons ().
The Weight of an object depends on the Gravitational Field Strength () of the planet or moon it is on. On Earth, (often rounded to for Grade 6).
Gravity is an attractive force that pulls objects toward the center of a planet or moon.
Relationship between Mass and Weight: Weight is directly proportional to mass. If you double the mass, the weight doubles, provided the gravitational field strength remains the same.
📐Formulae
💡Examples
Problem 1:
An astronaut has a mass of . Calculate their weight on Earth where .
Solution:
Explanation:
To find the weight, we multiply the mass () by the gravitational field strength ().
Problem 2:
The same astronaut travels to the Moon, where the gravitational field strength is . What is their mass and weight on the Moon?
Solution:
Mass = . Weight:
Explanation:
Mass does not change regardless of location. However, the weight decreases because the Moon's gravity () is much weaker than Earth's.
Problem 3:
A heavy box has a weight of on Earth (). What is its mass?
Solution:
Explanation:
By rearranging the formula to , we can calculate the mass of the object in kilograms.