Learners will further develop their understanding of gravity by comparing weight measurements here on Earth with those on other worlds in our solar system. Learners will be asked to publish a report on their findings.
Review what learners already know about gravity. You may wish to have them investigate Newton’s biography and findings in previous lessons. This software may also be used as an INTRODUCTION to Newton’s laws – they’ll want to know WHY objects have different weights on different planets!
You could have learners investigate their own weight on different planets, but we tend to avoid this approach (it can be a sensitive issue!) Divide the class into pairs or groups. Provide each with a selection of objects e.g. an apple, an iPod, a can of soda. It’s more effective to choose familiar/everyday objects that learners can relate to – this enlivens the ongoing discussions and discoveries!
Ask learners to weigh each object and make a note of it. When they have done this, direct the to the following website http://www.exploratorium.edu/ronh/weight/index.html and ask them to work systematically through their list of objects, inputting the ‘Earth weight’ in the ‘Enter you weight here’ box. They must record the corresponding weight for each object on each planet, moon, sun etc.
From this point onwards, the field of possibility really opens up! You could investigate why objects have different weights on other worlds, what are the limitation on us visiting other worlds, is an object’s mass affected, on which world would your weight in gold be most valuable, on which worlds would an air-filled balloon weigh the same as a lead balloon etc
Pupils should now use their notes to write a formal report on their findings. This can be published on a blog word processed and uploaded to Google Docs. Allow peers to read each other’s reports, and in the case of Google Docs, allow them to ask questions/make suggestions on the document. Before moving on, ask learners to review and resubmit their report.
What do I need?
scales (electronic are probably better, but any will do)
This software allows all learners, regardless of ability, to complete an inquiry as the software performs the calculations. Obviously, when the teacher deems it necessary, he/she will introduce the theories and calculations http://hyperphysics.phy-astr.gsu.edu/hbase/mass.html
Hints and tips
If the weighing equipment allows, allow learners to weigh their school bag! They love finding out how much it would weigh on Jupiter! Stick to one unit of measurement e.g. Kg Follow-on lessons could involve converting these e.g. Kg to tonnes. You may want to limit learners’ to 5 planets and the sun if you want to complete this in one lesson!