Chapter 1:Unit 15. Temperature

Temperature

Temperature is a measure of how hot or cold object is. It is defined as measure of average kinetic energy of the particle. In scientific world,

three Temperature scales are used. Fahrenheit, Celcius and Kelvin.

T_f= 1.8Tc + 32        Tk= Tc + 273-273.15 degree celcius is defined as absolute zero temperature. This is the lowest possible temperature theoretically possible in this universe. As temperature decreases, all energy of matter decreases as degrees of molecular and atomic motion decreases. A matter is expected to have all motion frozen at absolute zero temperature.

Watch the following video:

Example Problem:

State the Temperature on the Celcius Thermometer and convert into Fahrenheit scale.

Celcius: 61.5^oC
Applying the formula: Tf= 1.8Tc+ 32
1.8*61.5 +32= 142.7= 143^oF
Applying the formula: Tf= 1.8Tc+ 32
155=1.8Tc +32
155-32= 1.8Tc,
1.8Tc=123
Tc= 68.3 oC
Tk= Tc+273= 341.3K

Questions:

1. Why is the number 1.8 (and not some other value) used in the formula for converting between Celsius and Fahrenheit temperatures?

2. Convert the following Farenheit temperature into celcius and kelvin
3. 12⁰F
4. 32⁰F
5. 40⁰F
6. 212⁰F

Ans: 1. Since the ratio of calibration between two scales is 180/100= 1.8

2.a) -11⁰C and 262.15 K
b) 0⁰C and 273 K
c) -40⁰C and 233 K
d) 100⁰C and 373K