• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

To find out the difference in velocity it takes for a parachute to hit the ground with the same parachute model dropped at the same height but using different weights of plastacine (which represents the parachutist).

Extracts from this document...

Introduction

Rebecca Lee 10Y

Investigating the Free-Fall Velocity of a Parachute

Physics Practical Assessment: C4: Planning and Evaluating

Aim

To find out the difference in velocity it takes for a parachute to hit the ground with the same parachute model dropped at the same height but using different weights of plastacine (which represents the parachutist).

Introduction/Theory

Terminal Velocity is reached when the velocity becomes constant, so the drag is equal to the weight. The drag, which makes it fall slower, is mainly from the air resistance force trapped beneath the surface area of the parachute. A free-fall parachutist achieves terminal velocity because once dropped, the weight of the parachutist is equal to the drag force from the parachute.  The diagrams below illustrate the process of reaching terminal velocity.

1.                                           2.                                              3.      

The weight of the                    After a few seconds.                  After terminal velocity is

parachutist                                                                               reached.

(the plastacine ball).                            

The possible variables that can be used are:

  • The weight of the parachutist to see if it effects the acceleration.
  • The area of the parachute to see if it increases the drag.
  • The length of the parachute string to see if it increases/decreases the drag.
  • The height of which it is dropped from to see at which height would it hit the ground the fastest at.

Fair Test

To make this experiment a fair test and to control the variables it is considered that:

  • It will be dropped in a place which is not windy and made sure that it is redone if it bumps into something because it will affect the results.
  • The height of which it is dropped will always be measured 2 meters.
  • The same parachute will be used each time.

The changing variable is:

  • The weight of the parachutist, so each time 5 grams will be added on to see how it effects the time taken to hit the ground.  

Equipment

The equipment needed in this experiment is:

  • A plastic garbage bag for the parachute
  • String for the connecting rope
  • Plastacine for the weight of the parachutist
  • A metre ruler to measure the height
  • Tape and scissors for construction
  • A scale to measure the plasticine
  •  A timer to record the times
...read more.

Middle

Record results, and then change to a heavier ball and so on.

The way that I am measuring the free-fall velocity is by timing it from when it is let go and then when it first contacts the ground. Each time, the parachutist gets 5g heavier.

The readings I am going to record are done 10 times to get am average and timed using a stopwatch in seconds/milliseconds, so it is a more accurate answer.  

Results Table (also see graph)

Mass (g)

Try 1 (s)

Try 2 (s)

Try 3 (s)

Try 4 (s)

Try 5 (s)

Try 6 (s)

Try 7 (s)

Try 8 (s)

Try 9 (s)

Try 10(s)

Average (s)

Velocity

d/t (m/s)

5g

1.59s

0.97s

1.60s

1.37s

1.98s

1.47s

1.78s

2.10s

1.50s

1.79s

1.

...read more.

Conclusion

The different variables I could have used to extend my work were:

  • To change the area size of the parachute to investigate different drag
  • The height of which the parachute would be dropped from
  • The length of the string to see how it effects the parachute shape

I think that using these three variables would be useful to find out how the drag, height, and shape would effect the time taken for it to hit the ground. What I would expect to find out for these are:  

  • Size of parachute – it would take a longer time for the parachute to hit the ground as the size increases because a bigger surface area would mean that more air is trapped beneath the parachute surface holding it up for longer
  • Height – with a shorter distance, it would take less time to hit the ground, and with a longer distance, longer time.
  • Shape – the longer the strings, the time taken is shorter because of the weight as well as the shape is longer, so then there is less air trapped underneath a oval shaped area.
...read more.

This student written piece of work is one of many that can be found in our GCSE Forces and Motion section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Forces and Motion essays

  1. Marked by a teacher

    The aim of this experiment is to investigate what effect the surface area of ...

    3 star(s)

    Mass The mass of the parachute can be increased by adding an extra weight. The more the weight of the parachute is the faster the velocity should need to be in order to balance out the Air Resistance and therefore reach Terminal Velocity.

  2. Investigating the amazingness of theBouncing Ball!

    Therefore the return height reached by the ball will increase and so the decay constant will decrease. Method The rubber ball will be dropped from a height of 1m from the ground. This height will be calibrated with spirit measures and right angled traingles placed at the bottom to keep the metre rule perpendicular to the ground.

  1. Investigating the effect of mass on a parachute

    In addition, I am going to carry the method out so I can see if I need to make changes to the plan. Time Taken to fall down (in seconds) Mass (g) 0g 5g 10g 15g 1st Run 1.47 1.03 0.74 0.60 2nd Run 1.39 1.00 0.75 0.64 3rd

  2. Find out how a variable affects the terminal velocity of a parachute.

    Apparatus * Sticky tape * String * Plastacine * Plastic sheet * Ruler * Measuring tape * Stopwatch * Scissors Method 1. Use the plastic sheet and cut out a square that is 50x50cm. 2. Make a small hole at each corner of the square 3.

  1. Investigation on how the Surface area of a Canopy Affects the Rate at Which ...

    terminal velocity quicker and will fall at a steady speed to the ground. There is a difference of 1.59 seconds between a parachute with a surface area of 25cm2 and a one of 65 cm2 takes to fall the distance of 4.5 metres.

  2. The aim of this investigation is to find out how weight affects the terminal ...

    First I will cut out a 50x50 parachute out of a garbage bag. 2. Puncture holes in each of the corners. 3. Tie equal amounts of string to the parachute. 4. Make sure that the parachute weights 100g. 5. Choose a site to drop the parachute and measure the height of the fall.

  1. The Area of a Parachute Compared To Its Rate of Descent

    Following the first experiment, the second parachute can be made to similar proportions, but bigger. The sizes are shown below on the following table: Diameter of Distance of Length of Diameter of holes in top of string holes Length of string left after parachute (m) parachute (mm) from edge (mm)

  2. Test the effects of using a parachute of varying surface area on the terminal ...

    Equipment: Millimetre squared paper from which the parachutes are made String from which the 'cradle' supporting the mass is made Mass a constant 10g mass Metre sticks with which we measure the height of drop Protractor to adjust the parachute Stopwatch to time the drop Also: Scissors Glue Process of

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work