Alterations

I'm not sure why little bits of text keep getting changed around, but for the first example you're trying to find the pressure, which is f divided by a ( or 10 N / 5cm squared), which equals 2 N/cm.  This should help you work out the later questions.

Pressure in Fluids

https://docs.google.com/leaf?id=0BzFUvVu_WNI_Yjg4NTU5N2UtNWNmMC00OTc3LWEzNmEtMzFhOTQzY2M3OWRl&authkey=CNrI0bwE&hl=en

This is the link to the slideshow that we used today.  Remember that pressure = force x area, and then use the worked example on the slide to try the summary questions at the end.  We won't have another lesson until next Tuesday so make sure you have a go at this in the meantime!

Moments

We started pressure and moments today, and completed a practical on moments.  You need to remember that a moment is the turning effect of a force, and can be calculated by using the formula:

moment (Newton meters) = Force (newtons) x Distance from pivot (meters).

 So to lift or move something thats heavy using a lever you can either use more force or lengthen the distance between teh force (where you are pushing) and the pivot.  Tomorrow we will be using this to cover more material so make sure you know how to use the equation.

Gravity and Space

Now that we've finished the Gravity and Space section, I thought I'd put up a list of keypoints that you should know for the test at the end of the week:

1. Gravity is a force that exists between any two objects that have mass and aren't in contact. 
2. Mass is measured in kilograms and is the same everywhere in the Universe, weight is measured in Newtons and changes depending on the strength of Gravity.
3. Two types of satellites exist - Polar orbit which can be used to track weather systems or for mapping, and Geostationary which can be used to transmit TV and other signals.