Topic Two (1.2): Density and Mass

You will learn the first new relationship between different quantities. When you study a new relationship, please try to understand what happens with a given quantity when we change the other one, for example we double it. This will help you a lot when you solve problems.

This Topic will introduce your first new formula - as soon as you find any formula like the one on page 18, we would really recommend writing an abbreviated form onto a sticky note (simply ρ=m/v would be best) and put it somewhere you’re likely to see often. Include the appropriate units. Putting the letters rather than the full words keeps the information short so you can take it in at a glance, and also encourages you to engage your brain to remember what those stand for! Note that density employs an unusual set of units - in most situations you’d use kilograms for mass, but sometimes you’re using grams.

Interact

For this whole topic you will need to work through pages 18-23 in your coursebook, and answer the questions on pages 19,21,22, 24 and 25. The check-up questions cover topics 1.1 and 1.2.

Experiment

You could have a go at measuring the volume of irregularly shaped objects using a kitchen measuring jug and the method shown on page 20. If you also have kitchen scales, you could also determine the density of the objects. It is likely that your equipment is less accurate that the equipment in a science lab, but please do not worry, you can learn a lot by doing measurements yourself.

Links

Wolsey Hall subscribes to Twig and so we will use their resources a great deal in our Science courses.  Here is a Twig video on why objects float or sink.

WATCH - Buoyancy (Twig) [Link not available in sample course]

Here is a useful film which shows an experiment to measure density.

WATCH - Density - Required Practical (YouTube) Links to an external site.

Here are a couple of resources to help your understanding of density.  Please have a go at the questions.

READ - Density Poster Download READ - Density Poster

COMPLETE & CHECK - Density Questions Download COMPLETE & CHECK - Density Questions

The other extremely important thing to note in this topic is the difference between mass and weight. So many people get these mixed up because we’re used to using the words interchangeably in everyday life. Please remember that in science they are very different, and questions distinguishing the two are common in exams.

Links

Here are a couple of videos to help distinguish mass and weight.

WATCH – The Difference Between Mass and Weight (Veritasium) (YouTube) Links to an external site.

This one is just for fun.

WATCH – The Mass v Weight Song (YouTube) Links to an external site.

Extension

If you would like to study this topic in more depth or are aiming for grades A/A*or 7-9, please complete our extension worksheet. 

COMPLETE - Extension Worksheet 1.2  Download COMPLETE - Extension Worksheet 1.2 

CHECK - Extension Worksheet 1.2 Answers Download CHECK - Extension Worksheet 1.2 Answers