Year 7 Science · Unit 4 · Lesson 9

Tides and the Moon

Master Worksheet

Name
Date
Class

Learning Goals

Warm Up

Spring tide or neap tide?

Read each situation. Decide whether it describes a spring tide or a neap tide. Tick one box and give a short reason.

SituationSpring tide?Neap tide?Reason
It is a new Moon and the high tides are extremely high.
You see a half-lit quarter Moon and the tidal range is small.
The Sun, Earth and Moon are lined up in a row.
The Sun and Moon are at right angles to Earth.

Go Deeper

Analyse the tidal range over one month

Scenario

The bar chart below shows the daily tidal range (the height difference between high and low tide) at one Australian port across four weeks. A larger bar means a bigger tidal range. Use the chart together with what you know about the Moon to answer the questions.

Tidal range over four weeks: the range is largest in week 1 and week 3 (spring tides) and smallest in week 2 and week 4 (neap tides) Tidal range (m) Weeks 1 to 2 Weeks 3 to 4 Tall = big range Short = small range

(a) Look at the chart. In which weeks is the tidal range largest, and in which weeks is it smallest? Name the type of tide for each.

Challenge 3 marks

(b) Use the positions of the Sun, Earth and Moon to explain why the tidal range follows this regular up-and-down pattern across the month. Refer to the Moon phases in your answer.

Challenge 4 marks

(c) Evaluate this statement: "Because the sea is always moving, the tides are far too messy to predict." Do you agree? Justify your answer using the idea that tides are caused by the Sun, Earth and Moon, and use an Australian example such as Broome or the Bureau of Meteorology tide charts.

Challenge 4 marks

Wrap Up

In one sentence, what was the main idea of this lesson?

HSCScience · Year 7 Science · Unit 4 · Lesson 9 · Master Worksheet