This document outlines a laboratory activity to distinguish between mass and weight. The activity aims to: 1) distinguish between mass and weight, 2) learn how to use a force meter, and 3) understand that an object's weight depends on the planet's gravity. Students will measure the mass of objects using a balance, calculate weight using the equation for weight, measure weight using a force meter, and calculate weight on the Moon given its lower gravity. Results will be recorded in a table. Students will then answer questions about why weight is measured in newtons and whether an object's mass changes in different gravitational fields.

1. Physics & Chemistry Department
LABORATORY ACTIVITY 20: MASS AND WEIGHT
2nd ESO
Keywords
Mass, weight, gravity, force meter, balance.
Introduction
Are mass and weight the same? No.
Mass is the amount of matter in an object. It is measured in kilograms (kg) or grams (g). The mass of
an object can be measured using a balance.
The weight of an object is the pull force that acts on the object because of gravity. Since weight is a
force, it is measured in newtons (N). The weight of an object can be measured using a force meter.
Weight can also be calculated using this equation:
W=m·g
where W is the weight of the object, m the mass of the object expressed in kilograms and g gravity,
which depends on the planet the object is on (Earth’s gravity is 9.8 m/s 2 and the Moon’s gravity is 1.6 m/s 2).
Objective
The aims of this laboratory activity are:
-to distinguish between mass and weight.
-to learn how to use a force meter.
-to understand that the weight of an object depends on the planet the object is on.
Materials and apparatus
List all the materials and apparatus used.
Diagram
Draw a diagram showing the experiment. Remember to draw the apparatus in 2D, using a ruler, and to
label it.
Student’s laboratory activity 20: Mass and weight 1

2. IES Llorenç Garcías i Font María Pérez Galván; Emma Sánchez Clark
Physics and Chemistry Department
Procedure
1. Measure the mass of an object using a balance, express this mass in kilograms and record your
result in table 1.
2. Work out the weight of the object on Earth using the equation: W=m·g . Remember that Earth’s
gravity is 9.8 m/s2. Record your result in table 1.
3. Measure the weight of the object on Earth using a force meter. Record your result in table 1.
4. Work out the weight of the object on the Moon using the equation: W=m·g . Remember that
Moon’s gravity is 1.6 m/s2. Record your result in table 1.
5. Repeat steps 1 to 4 for another two objects.
Results
Table 1. Weight of the different objects calculated in two different ways.
Object m WEarth WEarth WMoon
equation force meter equation
(g) (kg)
(N) (N) (N)
Student’s laboratory activity 20: Mass and weight 2

3. IES Llorenç Garcías i Font María Pérez Galván; Emma Sánchez Clark
Physics and Chemistry Department
Questions
1. Why is weight expressed in newtons?
2. An object has a mass of 2 kg on Earth. Will it have the same mass on the Moon? Explain why.
Conclusions
Student’s laboratory activity 20: Mass and weight 3