The year fours have been learning about different forces, like ‘air resistance’.

 

Air Resistance is a type of friction that occurs between air and another material.

 

Air resistance is a force that acts on parachutes to slow a person’s fall to the ground. As the person falls the air pushes up against the parachute to slow them down.  Objects with more surface area will encounter more air resistance. This means objects with more surface area should fall to the ground slower because more air is pushing them up.

 

 

To test out the theory that more surface area will make an object fall to the ground slower we designed an investigation. We worked with a partner and made parachutes. One of us made a parachute with a larger chute surface area and the other made a smaller chute.  We then made sure to control all the other aspects of making the parachute so it would be a fair investigation.

 

 

Investigation Question

What happens to the rate that a parachute falls to the ground when we change the size of the chute?

 

Independent variable

– The size of the chute

 

Controlled variables

– The size of the animal on our parachute

– the number and length of strings on the parachute

– the height the parachute is dropped from

– dropping them at the same time

 

Dependent variable

– the speed the parachute drops to the ground (which one reaches the ground first)

 

Method

1. Get two plastic bags- one small and one larger.

2. Cut open the plastic bags to make a flat piece to use for the chute.

3. Cut eight pieces of string the same length.

4. Tape one pieces of string in each corner of both parachutes.

5. Tie the four pieces of string on each parachute together and attach to a plastic animal.

6. Take the parachutes outside and drop them from the same height recording which one reaches the ground first.

7. Repeat at least three times.

 

Results

It was a bit of a windy day when we trialled our parachutes so often they bumped into things and flew around the place. In general, most of the time the smaller parachute hit the ground first. This is because the smaller parachute has less surface area so not as much air can push it back up. The larger parachutes generally took longer to reach the ground. This is because it has more surface area so more air is pushing it back up whilst gravity is pulling it down to the ground.

 

Next time we could improve our investigation by doing our trial in a different location as the playground had lots of bits in the way that interfered with our investigation. We could also try trialling it on a day when there was less wind so our parachutes aren’t carried away. Another thing we could do was make our parachutes bigger or out of different materials. Some of our parachutes weren’t made very well and fell apart.