Parachutes & Drag

LO: Investigate how area can affect air resistance

How do parachutes work?

Your investigation• Design and make a parachute to provide

maximum AIR RESISTANCE for your sky-diver (a lump of plasticine)

• Time how long it takes to fall 2m• Repeat the test 3 times• Test three different sizes of parachute• Calculate the average time and speed for each

size parachute

Fill out your results tableSize of parachute (eg: small or 20cm3)

Time taken to fall ___ cm

Time taken to fall ___ cm

Time taken to fall ___ cm

Average Time (seconds)

Speed (s = d/t)

Use your average time for each parachute to work out the speed. Remember that:

Speed = Distance ÷ Time

To work out the average, add all the

times for each activity together and divide by the number of times

you repeated the activity (three)

Questions• Does the change in size of the

parachute make any difference. Why?

• How do the upwards and downwards forces on your parachute change as it descends?

• Would you do a parachute jump?!

Homework - Forces Diagrams

• Draw forces diagrams for a parachutist at three different stages of descent:– Start– Middle – End

• What two forces are acting on the parachutist?• Make sure you label your forces and that the size

of the arrows gives a clear indication of the size of the force

STARTThe parachutist has just

jumped out of the plane and is accelerating very fast

towards the earth!

MIDDLEThe parachutist is now travelling at a constant

speed

ENDThe parachutist has opened

his parachute and has slowed down

Air resistance Air resistance Air resistance

Gravity Gravity Gravity