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

# This investigation will look at the effects of air resistance on falling objects, where the objects will have the same dimensions but different masses.

Extracts from this document...

Introduction

DE COURSEWORK

Introduction

This investigation will look at the effects of air resistance on falling objects, where the objects will have the same dimensions but different masses. I will firstly model these situations to make predictions. This can then be experimented to obtain a set of results which we can use to test the models. The objects that we used were paper cake cups. We can change the mass by stacking these cups together, where stacking has no significant change on the overall profile as it drops.

Modelling Assumptions

As I am modelling this, there are assumptions that need to be made in order for the models to be more practical:

• The value of g (the acceleration due to gravity) is constant (9.81 m/s). This is probably not very significant as the actual mass of the paper cups is small, and so the value of g will be quite constant.
• The centre of mass remains the same. The assumption will not be very significant as the centre of mass would be quite constant.
• The paper cups reach terminal velocity. This is important as if the paper cups do not reach terminal velocity, we could get inaccurate values of k.
• The cups used are uniform with equal masses. Not very significant as masses of cups are very small variations in mass with other paper cups is very small. Also, the paper cups do have virtually the same surface area when stacked.
• There are only two forces which act on the paper cups, which are air resistance and weight, with no external forces (i.e. no downwards forces). This is quite significant as it could make readings inaccurate if there were any downward forces.
• The motion of the paper cups is one dimensional meaning that the cups will fall straight down, with no horizontal motion. Quite significant as there would be some sideways motion. But we assume this as there would be more complicated equations if not assumed.
• Model 1

Middle                  We then allocated people to each of the different heights to time how long the paper cups took to fall to that height, as well as a ‘dropper’ – the person who dropped the paper cups from the top floor. We started off with one paper cup and once the dropper was ready, he would shout ‘ready, steady, GO’, and at that point, all the timers would be started, and as soon as the paper cups passed each point, the timers would be stopped. The times were then recorded and this was repeated six times. We then repeated this for 3 cups and 5 cups.

Experimental Assumptions

We also have to make assumptions with the experiment, as we have to assume what occurs in the experiment is true:

• The paper cups have only downwards (vertical) motion, with no sideways (horizontal) motion.
• All timers start when the dropper signals ‘GO’ and are stop precisely once the paper cups have passed the interval
• The cup always is dropped from the same point
• There is no angular velocity of the cup, and hence no rotation
• The surface area of the cups is unaffected when more cups are added
• There are no external forces given to the cups, i.e. no downwards push
• Cups used are uniform with equal mass
• Initially the cups have no speed

Steps taken to reduce error

There were a few steps that we did to try and reduce the error in the results:

• We repeated the experiment 6 times for 1,3 and 5 cups and took an average time for each distance
• Closed all the doors in the building to try to minimise the drafts
• Chose a dropper who was good at letting the paper cups go as quickly as possible when the timer is started, without giving it a downwards push

Conclusion

Improvements in experiment

There are many improvements that could be made in the experiment to increase accuracy as well as to reduce any human/experimental errors. We could:

• Use light gates to time the paper cake cups, where the timer is stopped as soon as the paper cups pass the light gate
• Use an automated ‘dropper’ which is linked to the timers, where it starts all the timers simultaneously
• Drop the paper cup in a tube, so drafts do not affect the motion of the paper cake cups
• Conduct the experiment in a closed system, where air pressure, temperature will remain constant
• Take more readings to increase accuracy by taking an average

This student written piece of work is one of many that can be found in our AS and A Level Mechanics 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

# Related AS and A Level Mechanics essays

1. ## Mechanics Coursework

Obviously it is sensible to use Earth as the planet o choice. It would be interesting to investigate the difficulties of futuristic 'moon basketball' to take the investigation further. * I am also assuming that the basketball does not 'spin'.

2. ## Localization of Motion Perception the Cortex

All subsequent computations (object motion, three-dimensional trajectories, self-motion are based on these subsequent measurements. Exact boundaries of the parietal and temporal streams in humans are hard to specify. However a human parietal stream would presumably include area MT (V5), MST and possibly VIP and LIP.

1. ## One Dimensional Motion.

These equations can be further analyzed to see what took place in each test. Figure 5. Walking away and coming back Next the same CBL motion detector was taken outside to allow for enough room for the test and placed on a table.

2. ## This essay neither examines a mathematical equation, nor does it analyze a distinguished mathematician. ...

Background Even though he was not a mathematician, Zeno, better known as Zeno of Elea, was the first prominent doubter of the mathematical world. Born around 495 B.C. in the Greek colony of Elea in southern Italy, Zeno worked as a student under the philosopher Parmenides. • Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to 