See a Need…..Fill a Need

Year 7 Science 2006

Robots Movie

Inventions

• New ideas and inventions have all come about due to a need. Somebody has thought of an idea on how they think that they can improve upon life.

• All inventions begin with simple ideas!!

• At the end of the unit you will complete an inventions assignment, start thinking! It must contain 3 simple machines.

Simple Machines

• If you have used a door handle or a bottle opener today, or you have ridden a bicycle, you have been using simple machines.

• The most common simple machines are levers, pulleys, inclined planes (ramps), screws and gears.

• Complex machines such as cranes, winches, clocks and bicycles are a combination of many simple machines. Machines help you do things more easily. They do this in three different ways.

Clickable Worksheets

• Log onto the intranet and download the clickable worksheet– Intranet– Year 7 Science– See a Need……..Fill a Need Folder– Fill a Need Clickable Worksheet

Activity # 1 – Simple Machines

• Click on Start to begin the activity.

• Click on the house and complete the 4 activities.

• Activity # 1

• In your books, write down what each of the simple machines are (7 in total), including an explanation and diagram.

What machines do!

1. Machines magnify the force that you use.

2. Machines change the direction of the force.

3. Machines make things go faster.

Machines magnify the force that you use.

• Example:– When you have to remove a

nail from a piece of wood it is easier to use a claw hammer than your fingers. The larger the hammer the smaller the force needed to remove the nail. Machines that magnify the force you use are said to have a force advantage.

Machines change the direction of the force.

• Example:– When you have to pull

the sails up on your sailing boat, the pulley at the top of the mast makes it easier. You pull the rope down and the sail goes up.

Machines make things go faster.

• Example:– When you push on the pedals of a bicycle, the

back wheel turns much faster than the pedals. Machines that make things go faster are said to have a speed advantage or a distance advantage.

Simple Machines - Levers

• Suppose you want to move a large rock with a crowbar.

• A crowbar is a type of simple machine called a lever. A lever moves around a fixed point called the pivot (or fulcrum), in this case a small rock.

• The large rock is called the load, and the force you apply is called the effort.

Experiment # 1 - Levers

• Aim: To make several levers and investigate load.• Materials: Your leggo kit.• Method: 1. Booklet 4: Construct the first diagram on the inside

cover. Once complete show your teacher. Draw a diagram in your book, showing the pivot, load and effort.

2. Construct the diagram on the back page. Show your teacher. Draw a diagram in your book, showing the pivot, load and effort.

Question:What is the purpose of a lever.

Extension: Design a catapult.

Lever Questions

• Handout– P 181, 182 ( Scienceworld 7)

• Due: Wednesday 18th October

Simple Machines -Pulleys

• A pulley is a grooved wheel with a rope over it. A single pulley does not magnify your force. It simply changes the direction of the force.

• To magnify your force you need to use more than one pulley. This lets you lift very heavy loads by using only a small effort. However, you need a lot of rope to lift the object only a little way.

Simple Machines - Gears

• Gear wheels are wheels with teeth on them. The teeth of one gear fit into the teeth of another.

• Gears are used to transfer the force from one wheel to another.

Gears

Experiment # 2 – Pulleys and Gears

• Aim: To find out how pulleys and gears make it easier to lift loads.

• Materials: Leggo kit, Booklet 15, 16, 7• Method: 1. Booklet 15: Construct the model on the inside of the

booklet. Show your teacher. In your books, describe how the pulley works in 30 words or more.

2. Booklet 16: Construct the model on the inside of the booklet. Show your teacher. In your books, describe how the pulley works in 30 words or more.

3. Booklet 7: Construct the model on the back of the booklet. Show your teacher. In your books, describe how the gears work in 30 words or more.

Homework

• Handout

• P 190 Science world 7

• Due Wednesday 25 October

Clickable Worksheets

• Log onto the intranet and download the clickable worksheet: Compound Machines– Intranet– Year 7 Science– See a Need……..Fill a Need Folder– Fill a Need Clickable Worksheet

Activity # 2 – Compound Machines

• Now that we have discovered what simple machines are, many of the machines that we use have more than one simple machine in them. The Toolshed allows you to work out what the simple machines are inside a compound machine.

• Click onto the Toolshed.• Find and identify the four simple machine located in all of

the four compound machines.• Click onto all of the four machines and write down what

the simple machines are in the compound machines.

• Activity # 2

How things work!

• Problem 3– You are riding your bike when you come to a

steep hill. To ride up the hill you change gears. Do you use the largest gear wheel on the back wheel or the smallest? Do you use the largest gear wheel on the pedals or the smallest? Try to explain your answers.

– If you need help on bikes there is one in the lab.

Forces

• To understand how machines work, you need to understand how force is applied.

• Look at the cartoon on the next slide and find examples of:– Pulling Force (what is doing the pulling?)– Pushing Force (what is doing the pushing?)

Cartoon

• Pulling Force (what is doing the pulling?)• Pushing Force (what is doing the pushing?

Cartoon

• Which of the examples are:– Forces caused by

gravity– Lifting force– Forces where

something bends– Muscular forces– Electrical forces– Magnetic forces

Activity # 3

• The Odd machine.

• Go to www.edheads.org and click on the Odd Machine.

• Print off your score and glue into your book.

Robots – The Movie

• “See a Need…….Fill a Need” is a famous quote from Bigweld, the Greatest Robot in the World”.

• His existence has been to help other robots and make the word a better place to live in.

• Watch the movie and see why this quote is so important.

The Movie - Assignment

• Rodney found a need, to help his father. He invented something to help his father at work. He saw a need and filled it.

• Now it is your turn.– Find a need in your home, school or another place

and invent something that will make it easier or better for the people in that environment.

– You must invent something useful that contains simple machines such as levers, gears and pulleys. You must include 3 simple machines in your compound machine.

– “Let’s get to invent!” quote from Bigweld

Assignment Time

Test