1. PARACHUTES
J. A. Hargreaves

2. The Physics of Motion during a parachute jump!
Is it all it is cracked up to be?
I don’t think that I can add anything about the process of eco schools that is not covered already in the excellent websites The eco-school and now the brand new eco schools Scotland. These are informative and clear.
What I would like to address in my presentation is how eco schools can affect DHS

3. The instant the parachutist leaves the plane his vertical speed is zero!
Friction is zero
There is a force acting downwards -WEIGHT
The weight is an unbalanced force on the parachutist
The parachutist accelerates downwards according to Fw=ma. W
The parachutist accelerates at 9.8 ms-2

4. F Fun W As the parachutist falls his speed increase
AIR RESISTANCE/ DRAG increases
WEIGHT remains constant
There is still an unbalanced force on the parachutists but this is less than before.
The parachutist accelerates downwards but the acceleration is much less than 9.8 ms-2
Fun W
The parachutist does not slow down but speeds up slower!

5. F W Finally the magnitude of the AIR RESISTANCE is equal to WEIGHT
The forces on the parachutist are now BALANCED (overall effect ZERO)
The parachutist travels at CONSTANT VELOCITY (acceleration is zero)
The parachutist travels at TERMINAL VELOCITY W

6. F Fun W As the parachute opens AIR RESISTANCE/ DRAG INCREASES
WEIGHT remains constant
AIR RESISTANCE>>WEIGHT
There is an unbalanced force on the parachutist upwards
The parachutist decelerates
(slows down very quickly)
Fun W

7. IT IS TRUE THAT YOU GO UPWARDS WHEN YOU OPEN YOUR PARACHUTE
WHY DOES IT LOOK LIKE THAT ON THE TV?
The CAMERA MAN hasn’t opened his parachute yet! So he will be falling faster than the parachutist and will have to raise his camera up.

8. F W As the parachutist slows down
AIR RESISTANCE DECREASES until is equal to the weight
The forces on the parachutist are now BALANCED (overall effect ZERO)
The parachutist travels at CONSTANT SPEED
(acceleration is zero)
The parachutist travels at a new TERMINAL VELOCITY
(obviously less than before but still enough to break a leg on impact!) W

9. Fg Fun W As the parachutist lands
WEIGHT remains constant but there is a very big force from the ground
There is an unbalanced force on the parachutist upwards
The parachutist decelerates to a stop!
First thing required is to audit what is already being done.
First, Litter. Carried out checks at 09:30 and 15:30 and only significant litter was these two items.
There are plenty of litter bins, but do these, in their present form, enhance the environment? They could be in house colours, painted in the art lessons or just save up for new bins
Fun
PHEW! W