Bedienungsanleitung Knex 78610 - Education Intro to Levers and Pulleys Teachers Guide (Seite 56 von 62) (Englisch)

679357

Zoom out

Zoom in

Vorherige Seite

1/62

Nächste Seite

Teacher’s Notes

Force meters could be used to

compare the actual forces needed

to lift the weighted paper cup verti-

cally with those needed when using the

K’NEX block and tackle model.

An alternative approach could be

to use two force meters - one

representing the pulling force, or

effort, and the other the load to

be overcome by the effort.

 • Feeltheforceneededtolifttheweightedpapercup.

 • Howdoesliftingtheweightedpapercupwiththeblock

and tackle compare to lifting it directly by hand?

 • Countthenumberofstringssupportingthelower 

movable pulleys. What might this information tell you

about how much this block and tackle system helps

you to lift the load?

 • Usingtheblockandtackle,raisethecupabout5cm.

Measure how far the string must be pulled to allow the

paper cup to reach this height?

For either approach:

 • Askthechildrentodescribeandexplaintheir

observations, to make labelled drawings of their model

and use arrows to indicate movements. They should be

encouraged to use the correct terminology to describe

the different components.

Extension Activity 1

Design Task

Working in Groups of 2-3

The present lifting mechanism is not safe when in use.

Modify the design so that it will not topple when lifting

heavy objects.

The children should be encouraged to

(i) draw plans for their design

(ii) explain how they will evaluate it

(iii) write a description of how they think it will work.

On completion ask:

  •Whatchangesdidyoumakeduringthetestingof

your design?

  •Whatwerethemostdifficultpartstomake?

  •Howdidyousolvetheproblems?

The children should notice a significant

reduction in the effort needed to lift the

weighted cup when using the block

and tackle. They should also observe

that there are 4 strings supporting

the two lower movable pulleys. This

system makes it 4 times easier to lift

the weighted paper cup load, but the

‘trade-off’ is they have to pull the string

4 times the distance moved by

the load.

To promote the wider use and

application of ICT skills and practices,

the children’s models and work might

be recorded using a digital camera.

Extension Activity 2

Design Task

Working in Groups of 2-3

Yourmotherisaphysicaltherapistworkingwithpeople

who have been injured and have to use wheelchairs. It is

often difficult for your mother to lift the patients out of their

wheelchairs to use the machines for their exercises. Using

K’NEX and other appropriate materials, design and make

a portable pulley system that can lift patients out of their

wheel chairs and transport them to the different exercise

machines. Explain how your machine operates and how it

uses pulleys to accomplish the task.

levers and pulleys

website: www.knexeducation.co.uk

Lesson 9: The Block and Tackle

Education

Missbrauch melden von Frage und/oder Antwort

Libble nimmt den Missbrauch seiner Dienste sehr ernst. Wir setzen uns dafür ein, derartige Missbrauchsfälle gemäß den Gesetzen Ihres Heimatlandes zu behandeln. Wenn Sie eine Meldung übermitteln, überprüfen wir Ihre Informationen und ergreifen entsprechende Maßnahmen. Wir melden uns nur dann wieder bei Ihnen, wenn wir weitere Einzelheiten wissen müssen oder weitere Informationen für Sie haben.

Knex 78610 - Education Intro to Levers and Pulleys Teachers Guide Seite 56

Brauchen Sie Hilfe? Stellen Sie Ihre Frage.

Missbrauch melden von Frage und/oder Antwort

Art des Missbrauchs:

Forenregeln

Neu registrieren

Andere Handbücher von Knex 78610 - Education Intro to Levers and Pulleys Teachers Guide

Das Handbuch wird per E-Mail gesendet. Überprüfen Sie ihre E-Mail.

Ihre Frage wurde zu diesem Forum hinzugefügt

Info