A second balloon launch

Yesterday we had another pair of balloons launched from Brambletye. The GPS system sent us some interesting but possibly unreliable data. The balloon either went up to 11.5km high or 7.5km high and stopped sending data when it was out at sea south of Newhaven. It may even have floated as far as France! More tests required. Here is the launch:

IMG_3178 from Brambletye on Vimeo.
IRP

CE revision course at Easter

Having reviewed the exam results this term we feel that the current Year 8 pupils have made particularly good progress with the Chemistry syllabus. It is therefore a good idea that the science revision course on 14th and 15th April should be more general rather than focus solely on Chemistry. As a relatively small number have signed up so far we will be able to tailor the course to the needs of those who attend.
IRP & MH.

Brambletye Space Program Test 1

Yesterday our budding astronauts and cosmonauts set off a couple of helium balloons as test flights for our Brambletye Space Program.

First the balloon needs to be partially filled with helium.

The balloon will get bigger as it gains altitude because atmospheric pressure decreases with altitude.

Then the tracking equipment and a small parachute need to be attached.

The parachute will control the descent rate to about 5m/s.

The tracking equipment needs to be ready and receiving signals from the balloon.

We needed to launch from a site well away from trees

 The balloon is ready

10, 9, 8, 7, 6, 5, 4, 3, 2, 1.

 

And off it goes

Up, up and away

The trackers give us vital information:

First line is all about signal strength and frequency

Second line shows the time and the N coordinates

Third line shows battery life and the W coordinates

fourth line shows speed in knots, Altitude in m and temperature in degrees C

We used the coordinates in google maps to track where the balloon was.

This is near its last message.

 We had two receivers for each balloon just in case one failed. The picture shows the last message each received. The balloons were still going the highest one was at 8.5km altitude, doing 66 knots (that's about 120kph) and the temperature was -54 degrees C. In all likelihood the batteries failed at this very cold temperature. It was 175km away from school and still going strong!
I would like to say a very big thank you to the enthusiastic Dads who have helped with their expertise and equipment. Without them this project would not have been inspired yet alone realised.

 

 

 

 

 

 

 

 

 

It is Rocket Science

 Yesterday Y7 used their knowledge of pressure

to launch rockets. 

 First you need to add some water.

This will be the propellant

Different amounts were used each time by some groups 

 Measured carefully of course

 So that it was an accurate investigation

The rocket was attached to a pump 

and pumped to increase the pressure inside the bottle

It builds up and up.

The excitement builds

And the rockets fired 

 pushing the water out backwards

so they shoot forwards (Newton's third law of motion) 

"Every action has an equal and opposite reaction" 

Lots of groups all working harmoniously

Some groups tried different amounts of water each time

 Some tried different angles of the gutter launch system

They all shot across the terrace

 and the length od flight was measured

 And then written down.

Year 6 determine the speed of sound by experiment

It was a lovely sunny day on which to do a very large experiment. Finding the speed of sound.

 We needed a large distance so we went to the Nevill field

Speed = Distance / Time so we need to measure the distance.

This was done with a trundle wheel

and a lot of counting!

We checked it a few times

to make sure the result was reliable

as there are a lot of clicks to count

and the listeners kept moving (but not much).

We put our sound source at the other end of the long distance

The clapper board was used to make a loud bang

We can see the boards crashing together and that's when we started the timers

Then  we stopped the timers when we heard the sound a fraction of a second later

 

 

and wrote the times down

 We did this many times so we could try to rule out any errors

 We changed jobs too so everyone got to experience seeing the clapper crash shut before hearing the bang a moment later.

 This is why you see the runners start a moment before you hear the starting pistol when you are by the finish line on Sports Day. Also why the bat seems to hit the ball before you hear it when you are watching cricket on the boundary. Fireworks do the same, flash of light before you hear the big bang and its why if you look at where the sound is coming from you wont see the aircraft that's making it. The plane will be further ahead well in front of its sound.

We have all of the data now so next lesson we will have to do some calculations and see if we have an accurate result.

 

 

 

7C have fun with Dry Ice

7C had a little experiment with dry ice in the lab today.

 This is solid carbon dioxide, at -78 degrees C

which will sublime into gaseous carbon dioxide 

 without going through the liquid phase

 so when you put it in hot water

 it sublimes really quickly.

Hence it gives off very cool carbon dioxide gas 

 but this is NOT the smoke you see

That is a cloud! 

 That's right we made clouds in the lab

 The cold carbon dioxide reduces the temperature of the air above the water

 which means it can't hold so much water vapour

so it condenses forming microscopic water droplets

OR clouds!

Look at the previous blog entry to see the dry ice Hero Engine.