Parachutes D. Crowley, 2008

Parachutes To be able to make parachutes which will travel at different speeds Friday, August 07, 2015

Air Resistance How could you investigate the factors that affect the air resistance of a parachute? What could you change? How could you measure the air resistance? To investigate the air resistance of parachutes we could change the size of the parachute and its shape To measure the air resistance we could measure the speed or the time taken to fall a known distance (weight can be kept constant, so the speed will indicate how much air resistance there is)

Prediction Write a prediction for what you think will happen – consider what happens when the parachute size and shape are changed, adding key scientific ideas We should find that as the parachute gets bigger there is more air resistance, so the parachute will fall slower. Shape variations will also affect the speed descent, depending on the amount of drag they exert

Results Table Copy down the results table, ready for our experimentation Size of parachute (cm) Time taken for parachute to fall to floor (sec)Speed of parachute (distance ÷ time) Drop 1Drop 2Drop 3Average Speed Distance Time Distance dropped (height of parachute when released) __________ (meters)

Making The Parachute 1.Cut out 4 different sized squares from a piece of plastic (recording the sizes in your table) 2.Cut 4 pieces of cotton (30cm long) 3.Tape a piece of cotton to each of the 4 corners of the parachute 4.Tie the other ends to your mass – now the parachute is ready to test!

Experiment 5.Now measure the height at which you will drop your parachute (record this as the distance dropped) 6.Drop your parachute, timing how long it takes to hit the ground - repeat your experiment three times for each parachute 7.Repeat this experiment, using the different sized parachutes…

Analysis Explain your findings Which parachute had the fastest speed and why Which parachute was the slowest? Use the following key words for help: air resistance; gravity; slower; weight; mass; area; faster Finally describe how you could improve this experiment

Force Diagrams Draw two force diagrams, for your fastest and slowest parachutes, adding the correctly sized force arrows