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

Efficiency Lab

Extracts from this document...

Introduction

Anthony Leung

Block E

Bow and Arrow Lab – Efficiencyimage00.png

Research Question: How does efficiency with which the bow transfers energy to the arrow depend on the mass of the arrow?

Hypothesis: Efficiency will increase as the mass of the arrow increases, as Eff= Eout/ Ein.

Variables:        Independent – the mass of the arrow. In this procedure, this variable was calculated by weighing with an electronic balance to ascertain and acquire the margin of error. A series of different massed arrows were used to determine the change in efficiency of the energy transfer from the bow and to increase the level of precision.

        Dependent – efficiency with which the bow transfers energy. The dependent variable is the resultant, or the value that we are attempting to measure. As the equipment to measure this is out of our reach, we can only to calculate this value.

        Controlled – the height of the bow. The height of the bow is kept at a constant height in order to maintain the precision of the procedure. If

...read more.

Middle

8

6.88

9

Note: The percentage error is an approximate value and is present due to human and equipment errors. The equipment used will always contain a certain degree of uncertainty and lack the precision present in technology beyond the reach of high school students

Displacement of Bowstring

Arrow

Displacement (cm) ± 0.05

1

9.0

2

9.0

3

9.0

4

9.0

6

9.0

8

10.0

9

10.0

Note: There is a certain degree of uncertainty involved in these measurements due to error in human sight and error in the metre stick. It is impossible to have the bowstring exactly at a certain measurement, so the uncertainty is present.

Displacement of Arrow

Arrow

Displacement (m) ± 0.1

1

0.87

2

0.48, 0.50, 0.58

3

0.64

4

0.76

6

0.30, 0.50

8

0.65

9

0.32, 0.38, 0.78, 0.2

Distance from floor to rail: 3.0 m

Distance from floor to bow: 0.70 m

...read more.

Conclusion

Limitations: The range of uncertainty for this procedure is very large, due to error in human sight, and error in measuring tools such as the measuring tape and the metre stick. For one, we do not know exactly the distance the bowstring is pulled back each time. The distance 9.0cm is a rough estimate, as we lacked the time to properly measure. Another limitation is the recorder at the top of the railing. As we can only roughly estimate the maximum height of the launch, there is a huge variance.

Improvement: Perhaps a more realistic method to perform this procedure is to attach some sort of string to the arrow. When launched into the air, the arrow will go up, bringing the string with it. During the peak moment, where there is a very brief pause, we will place a mark on the string (from the floor) and then measure afterwards. Therefore, the limitation of human sight can be lessened. However, the string must be long enough and be light enough as to not corrupt the precision of the experiment. Of course, there will be a degree of error involved, but significantly reduced and smaller than the present one.

...read more.

This student written piece of work is one of many that can be found in our International Baccalaureate Physics 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 International Baccalaureate Physics essays

  1. Current Balance

    Thereafter is a graph showing the relationship between F and IB. The graphs very nearly do go through the origin. Therefore to calculate the slope we need to find F over IS. The slope for when IB = 4A is 4.55 10-4.

  2. Design Lab, Charge on Balloons

    * 1 Weighing scale (�0.1g) o The weighing scale will be used to measure the mass of water dispersed by the balloon so that the volume of the balloon can be determined (as stated by Archimedes principle) * 1 Electroscope o The Electroscope will be used to measure the charge on the balloon using conduction.

  1. Forces Lab. I decide to investigate the relationship between the propelling force exerted on ...

    repeating experiments for each of 4 different masses of the hanging weights. Mass (kg) Symbol: m Total distance 1 (m) Symbol: Total distance 2 (m) Symbol: Total distance 3 (m) Symbol: Average total distance (m) Symbol: 0.10000 0.65 0.63 0.64 0.64 0.15000 0.87 0.87 0.85 0.86 0.20000 0.99 0.97 1.00

  2. Pendulum Lab

    Time measurement device- To increase the accuracy and diminish the significance of human error in counting, a stopwatch was used to keep track of the duration of the pendulum's period.

  1. Physics Wave revision question

    Which one of the following diagrams is a possible subsequent picture of the string? (1) 26. A water surface wave (ripple) is travelling to the right on the surface of a lake. The wave has period T. The diagram below shows the surface of the lake at a particular instant of time.

  2. Physics Lab

    and g is the acceleration due to gravity that every body on the earth feels. g is taken to be around 10ms-2. For example: 1Kg = 1000g � 100g � 1000g = 0.1Kg 1Kg = 10N � 0.1Kg � 10N = 1N.

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