__________________________________________1Kismet_________________________________________

Tuesday, July 13, 2010

short revision for the physics PRACTICAL test @ 10:09 PM

Hey people! Here is a short revision for the physics PRACTICAL test! Ya’ll can just read through.

Temperature and Thermometers

1. K = C +273

2. Thermometric property = A physical property that changes continuously with temperature (Also memorise the table on Pg 3 of 11 of Notes 1)

3. Steam point and Ice point CANNOT be changed.

· SP = Temp. of steam from boiling water at a pressure of one standard atmosphere.

· IP= Temp. of PURE melting ice at the pressure of one standard atmosphere.

4. Differences between Alcohol & Mercury

Property	Mercury	Alcohol	Advantage/ Disadvantage
Colour	Silver	Transparent	Alcohol cannot be seen and needs to be dyed. (Change boiling point/ Melting point due to impurity)
Freezing point	-39 DC	-115 DC	Alcohol can measure lower temp.
Boiling Point	357 DC	78 DC	Mercury can measure higher temp.
T conductivity	High	Low	Mercury more responsive
T expansivity	Low	High	Alochol more sensitive
Adhesion to glass?	Does not stick	Stick to glass	Mercury gives a more reliable reading.
Uniform expansivity?	Uniform	Not uniform	Mercury gives a more reliable reading.

5. 3 main characteristics of Thermometers:

· Responsiveness : How QUICKLY it changes

· Sensitivity: How MUCH it changes

· Range: How much it can MEASURE

6. Read up pg 146 of the Physics TB

7. Clinical Thermometer:

· Measure 35 DC to 42 DC. Narrow constriction to prevent liquid from flowing back into the bulb to allow time for measurement

· Cross-section is pear-shaped to magnify the liquid

How Scientists Work

1. Remember how to use a Bunsen Burner:

1) Put on goggles and turn the collar to close the air-holes

2) Hold the lighter over the top of the barrel

3) Turn on the gas tap

4) A luminous flame will appear

5) Turn the collar to open the air-holes if a higher temperature is needed.

6) A non-luminous flame will appear.

7) Turn off the gas tap.

8) Place goggles and lighter back into tray

2. Remember to read measurements with EYE LEVEL at the TOP OF MENISCUS of the Thermometer.

3. If an experiment involves putting a thermometer in blah blah and such, make sure the following words appear in your procedure:

· Place thermometer VERTICALLY using the clamp

· Record the STEADY temperature

4. If Record of Measurements is required and you need to draw a table, remember to:

· Draw the table in PENCIL and write down the words in PEN

· Write the measurement unit in Thing being measured/unit

· Not to repeat the MEASUREMENT UNIT in your record

· To include a PRECISION of maybe 0.5 in a laboratory thermometer and 0.05 in a clinical thermometer

5. Remember the 3 types of Variables:

· Independent: Intentionally changed

· Dependent: Factor that might be affected by IV

· Constant

6. If you are drawing a diagram, please LABEL and TITLE the diagram.

7. 7. Read up and memorise the FUNCTIONS of the APPARATUS of things like evaporating dish, Retort stand, test tube, etc.

FAQ

· Explain why you feel colder when you enter an air-con rm after a hot bath as compared to when you enter a rm at rm temp.

è The TEMPERATURE of the air-con rm is lower than the rm at rm temp.

è The body after a hot bath will have a HIGHER EXTERNAL BODY TEMP.

è The body's temperature difference with the rm at rm temp. is smaller as compared to the air-con rm and thermal energy transfer is smaller.

è When thermal energy transfer is faster, the body will feel colder.

· Is the sense of touch a good way to measure temp. of an object accurately? Why?

è No.

è Detect a range of temperature only

· Why is the skin not a good sensor of temp.?

è Will determine a wrong range when the skin if affected by a previous object after measuring

· What makes a good thermometer?

è Easy-to-read scale

è Responsive & Sensitive to slight temp. changes

è Able to measure a wide range

· Why clinical thermo. Has a short range?

è Designed to measure body temp. which stays at about 36.9 DC.

· Why clinical thermo. cannot measure rm temp.?

è Rang of rm temp. is 28 DC to 35 DC.

· Why ice shavings are used instead of ice cubes when measuring melting point of ice?

è Ensure good thermal contact w/ e bulb

è Result will be accurate.

*P.S. If there is anything you want to add or change, just tag ^.^

____________________________ ★ 1kismet ★ ____________________________