ceann chalker [email protected] patrick chalker [email protected]
TRANSCRIPT
Students will make:Metric Estimations
thenMetric Measurements
on identical objects
*Mass
*Volume
*Density
*Area
*Force
*Distance
*Time
*Temperature
*Students rotate between 15-30 stations for each of the two parts of the event
*Supervisors furnish all pencils, paper, and measuring devices
*Teams may bring non-programmable calculators for the Measurement Part only.
*Property to be estimated/measured and Units of Measurement will be given at each station.
*Approximately 30 seconds for each station
*All answer recorded on form provided by Event Supervisor
*Answer form MUST be turned in before Measurement Part begins
*Students may not use any kind of measuring device (fingers, pencils, clothing, paper, etc.)
*Students may not Touch or Feel any objects unless specified in directions
*NEW!!! Students MUST be allowed to “heft” an object if the mass is to be estimated.
*Approximately 60 seconds per station
*All answers recorded on new form provided by Event Supervisor
*Measurements are made using the instruments supplied at each station
*All objects will be measured by the Event Supervisor prior to the competition using the same instruments the students will use
*To receive points, 3 requirements*Proper Resolution
*Estimated digit Appropriate for the Instrument
*Proper Unit of Measurement
Ex. – Answer should be 17.25 grams or 17.25 g on a standard Triple Beam balance
Wrong answers would include –
17.2 grams, 17.2 g, or 17.25
*Direct Measurements - not involving calculations, readings directly from an instrument (e.g. length, volume, mass, etc.)
*Calculated Measurements - measurements that require mathematical calculation to achieve (e.g. calculating the density of an object, height using triangulation, surface area, velocity, etc.).
*Students record measurement to +/- 3 of the estimated digit of the instrument’s resolution.
*Direct Unit Conversions are considered Direct Measurements.
*The smallest actual graduation or markings on the instrument
*A rock has a mass of 56.54g. Using a triple beam balance to find that mass.
*A line on the floor is 187.43cm. Using a meter stick to measure the line a student adds 100cm to 87.43 cm to come up with 187.43cm
Ruler has the smallest resolution of 1 mm*Width of object #1 - Measurement of 209.3 mm
* Answers between 209.0mm - 209.6 mm would be correct
Triple Beam Balance has smallest resolution of 1/10th of a gram
*Mass of rock – Mass of 37.26 grams
*Answer 37.23 grams – 37.29 grams would be correct
*Students take direct measurements and make mathematical calculations obtain the correct answer.
*More difficult to obtain exact answer
*Various points are awarded for answers within .5%, 1%, and 2% of the correct value.
Surface Area *A rectangular box with dimensions 10.62 cm x 4.63 cm x 4.63 cm. To calculate the surface area 2(4.63x4.63) + 2(4.63x10.62) + 2(10.62x4.63) = 42.8738 + 98.3412 + 98.3412 = 239.5562 cm2
*A circle with the diameter of 9cm, the area of that circle is 3.14159 x 4.52 =63.6171975 cm2
*Both parts (Estimation and Measurement) are rated on accuracy
*Rankings are the highest combined score
*Three separate methods of scoring are used
Points based upon the percentage of the correct value for each station
*5 pts – Answers within 5%
*3 pts – Answers within 10%
*1 pt – Answers within 20%
*5 pts – Answer expressed to the instrument's resolution +/-3 of the estimated digit
*0 Pts – All other Answers
Points based upon the percentage of the correct calculated value for each station
*5 pts – Answers within 0.5%
*3 pts – Answers within 1.0%
*1 pt – Answers within 2.0%
*0 pts – All other answers
*Break everything down to the fundamentals
*Useful Formulas
*Finding new things to measure
*Conversions and units
*Comparing size and mass to known objects
*Estimating time by average
*Crazy (but measureable) stations
*Measuring irregularly shaped objects
*Massing something on an open hand
*Using a triple beam balance under time constraint
*Items that seem easy but are very difficult
*Approaching measurements in the same way EVERY TIME
*Practicing measuring with time
*Coaching confidence (and a bit or arrogance)
*Teamwork, dividing the workload
*Mental math
*Put school name and team # on EVERYTHING!
*Put labels for units on EVERYTHING!
*Look at the measuring tool first, and then the object to measure second.
*Check to see if measuring devices are zeroed or in need of zero-ing.
This is just a sampling of formulas students should know, there are many more to learn.
*F=ma, Force = mass x acceleration
*A=∆V/∆T (Acceleration = change in Velocity divided by Change in time)
*A=(V2-V1)/(T2-T1)
*SA = πr2 + πrl (surface area of a cone)
*SA = 2ab + 2bc + 2ac (surface area of a rectangular prism)
*Surface Area of a Sphere = 4 pi r 2
*Surface Area of a Cylinder = 2 pi r 2 + 2 pi r h
*g=-9.81 m/s2 (Earth’s gravitational constant)
*1 N = 1 kg (m/s2)