iSTEM Stage 5 Aeronautics – Gliders -Resources

iSTEM        STAGE 5 Aeronautics  – Gliders

Resources

 

 

 

 

 

Year 10 Bionics

BIONICS

Many people today live active and productive lives because faulty parts of body can be replaced by new materials and new devices.  These materials and devices can have a significant impact on a person’s quality of life and the length of life.

 Bionics is the use of electronic and mechanical devices that copy the behaviour of parts of the human body.  Through scientific knowledge gained on the biological systems, engineering systems, and artificial intelligence, scientists continue to extend their understanding of biological principles to solve engineering problems.

Prothesis Is an artificial body part (replacing or supporting a natural part of the body eg – teeth, eye, bone)

 

BIOMATERIALS:

By studying the structure of living things, chemists learn about arrangement of molecules and use this knowledge to produce synthetic materials that are hard or soft, stiff or elastic, just like the real thing. These special materials – able to function with living tissue, with minimal ejection by the body – are called biomaterials.

BIODEVICES:

Engineers make devices  from biomaterials and designed to perform specific functions in the body are generally referred to as biomedical devices or implants.

Scientists use the principles of engineering coupled with a knowledge of the functioning of organs and body systems for development of therapeutic devices such as artificial body parts and systems such as artificial blood vessels, pacemakers, dialysis equipment and artificial limbs.

Prosthetic Devices

Many devices currently used in the human body as artificial organs and prosthetic devices.

An organ is a specialised structure (e.g. heart, kidney, limb, leaf, flower) in an animal or a plant that can perform some specialized function.  These varied parts (organs) sometimes become defective and must be replaced by an artificial organ or a prosthetic device. These replacement devices are constructed of natural or synthetic polymeric materials. Such biomaterials must exhibit good compatibility with the blood and the body fluids and tissues with which they come into contact. Artificial device must closely duplicate the function of the natural organ. In practice, these artificial devices are constructed from a wide variety of materials such as metals, ceramics (including glass and carbon), natural tissues (actually polymeric in nature), and synthetic polymers. Partly due to the wider range of properties available, most of these artificial devices are constructed wholely or partly from natural or synthetic polymers. Obviously the same polymer could not be used for all possible artificial organs or prosthetic devices. Rather, the material to be used must be matched to the specific use requirements. Artificial organs can conveniently be classed into four groups: (I) Bone/Joint Replacements (e.g. hip, knee, finger, total limb), (II) Skin/Soft Tissue Replacements (e.g. skin, breast, muscle), (III) Internal Organs (e.g. heart, kidney, blood vessels, liver, pancreas), and (IV) Sensory Organs (e.g. eye, ear).

 

 

 

Body Part Biomaterial used or

Biomedical device used

Reasons for use

of artificial device

Head, Limbs, (Skeleton) Pins, screws and plates Broken, crushed bone
Knee, Hip, Elbow, Knuckles Artificial joints Degeneration, damaged
Ears Cochlear implants Replace damaged inner ear
Heart Pacemakers Irregular heart beat
Heart, arteries Artificial valves Valves not functioning correctly
Teeth Crowns, dentures Tooth decay, Broken teeth
Eyes Lenses Damage caused by cataracts
Arms. Legs Prosthetic limbs Loss of limb by disease, accident

 

Year 10 Stage 5 Universe Star Formation

Star formation – What you need to know……

 

  1.  Gravitational force is responsible for producing stars from interstellar cloud of gas called nebulae
  2.   Gravitational  continues to cause clouds of gases  (hydrogen) to aggregate (come close together) . Hydrogen atoms gather due to gravity force and undergoes nuclear fusion to form helium) and  form protostar. This goes on to form our Sun is also a star.  Among all the stars, it’s the nearest to the Earth, and so it appears big from seen from the Earth
  3.   Planets are the celestial bodies that revolve around a star and do not have any heat and light of their own.
  4.   Planets are smaller than stars and reflect the light of the sun.
  5.   Earth, on which we live, is one of the planets which revolve around the Sun.
  6.   A star and the planets revolving around it form a planetary system, just like our Solar System.
  7.   A group of stars along with their planetary systems form a galaxy.
  8.   The galaxy in which we live is spiral in shape and is called the Milky Way.
  9.   It contains over 200 billion stars, including the Sun.
  10.   There are billions of galaxies in the universe.
  11.   Life cycle of stars: (how stars is born and their transformations).
  12.   Red giant: a star produced when the core of Sun-sized star ran out of hydrogen
  13. Supernova: a giant explosion that occurs when a star many times larger than our sun ran out of nuclear fuel.
  14. White dwarf: hot dense star that is the remains of a red star.
  15. Black hole: is a collapsed star (due to very strong gravitational force) that even light cannot escape from it.
  16. Main sequence: a group of star lying in the line of the Hertz sprung Diagram running from top left to bottom right
  17.  Blue supergiants stars are ten or more times more massive than the Sun.
  18. Black dwarf: cold dark remains of a white dwarf.  (see number 23 above)
  19. Neutron star: remnants of  supernova consisting of entirely neutrons

STAR CHART:

 

 

Year 12 Scientific Skills – Errors

WORKING SCIENTIFICALLY: ERRORS, Fair Test etc.

 

  1. Outlier/Anomalies     

These are values in a set of results which are judged not to be part of the variation caused by random uncertainty.

 

Question 1: Matthew records the current in a resistor for a certain voltage and takes repeat readings, some of which are shown below:

 

Resistance (Ω) current (A)
1 2 3 4 mean
20 0.25 0.28 0.47 0.26
30 0.16 0.17 0.15 0.16
  1. Highlight the anomaly/outlier  in the table.
  2. Correctly determine the mean for each row.

 

  1. Measurement error: The difference between a measured value and the true value.

 

Question 2:  Simon measures the mass of a mug as being 250 g, but its true value  is actually 260 g. The difference is a measurement error.

(True value is the value that would be obtained in an ideal measurement. An ideal measurement is one that would have no errors at all)

           Calculate the percentage error in Simon’s measurement.

 

  1. Uncertainty

The interval within which the true value can be expected to lie, with a given level of confidence or probability, e.g. “the temperature is 20°C ± 2°C, at a level of confidence of 95%.”

The symbol ± is called “plus or minus”, and in the example above means “plus or minus 2°C” – i.e. the temperature is most likely to be between 18°C and 22°C.

The “level of confidence” expresses how certain the scientists are of their claim that the temperature is in the range 18—22°C.

 

Question 3:(a)  State the mean and the uncertainty for the following data:

                   33, 36, 28, 37, 29, 27, 30, 31

              

Question 4: In conducting an experiment comparing the speed of sound to the air temperature, Amasha’s thermometer has units of 1 o C and you have found the air temperature to be 20 o C. Calculate

  1. The absolute uncertainty
  2. The percentage uncertainty.

 

  1. Random Errors

 

These cause readings to be spread about the true value, due to results varying in an unpredictable way from one measurement to the next.

Random errors are present when any measurement is made, and cannot be corrected. The effect of random errors can be reduced by making more measurements and calculating a new mean.

Random errors may be caused by human error, a faulty technique in taking the measurements, or by faulty equipment.

 

Question 5: Fawad and Andrew are both timing a very fast pendulum with a stopwatch. Andrew can’t count the swings accurately as it is just too fast to keep up – this introduces a random error in his readings as he may think he has counted 20 swings when in fact it was 21.

Fawad doesn’t use the stopwatch very well. Although he starts it fairly accurately, he panics when having to stop it and is either too early or late. This is a random human error.

 

Suggest how Fawad and Andrew can improve the reliability of their data. Explain your answer.

 

Question 6: Matthew records the current in a resistor for a certain voltage and takes repeat readings, some of which are shown below:

Resistance (Ω) current (A)
1 2 3 4 mean
20 0.25 0.28 0.47 0.26
30 0.16 0.17 0.15 0.16

 

  1. Explain how Matthew’s table shows a random error.
  2. Explain how to improve the accuracy of the data in Matthew’s experiment.

 

  1. Systematic errors

 

These cause readings to differ from the true value by a consistent amount each time a measurement is made.

Sources of systematic error can include the environment, methods of observation or instruments used.

Systematic errors cannot be dealt with by simple repeats. If a systematic error is suspected, the data collection should be repeated using a different technique or a different set of equipment, and the results compared.

e.g. A systematic error occurs when using a wrongly calibrated instrument.

E.g. Ashley’s pendulum timing experiment was made worse by the fact that she also began counting at ‘1’ not ‘0’. So all her times, in addition to random in her counting, were also short of one full swing each making her calculated times all smaller than the ‘true values’.

 

7 FAIR TEST

A fair test is one in which only the independent variable has been allowed to affect the dependent variable.

A fair test can usually be achieved by keeping all other variable constant.

 

 

Question 7

Swee Yong and Pavan are investigating how the electrical resistance of wires changes with length. Unfortunately both of them let the current get too high for shorter wires, which dramatically increases their temperature. Since temperature affects resistance (in addition to the length), it is not a fair test.

 

  1. Identify the independent and dependent variables in their investigation.
  2. Explain why their experiment is not a fair test.  
  3. What could they do to make it a fair test?