Measuring temperature

Measuring temperature

Teacher: Mr. Waite

Lesson Objectives

• Define the term temperature.

• Read the instrument used to measure temperature.

• Convert temperature from degrees Celsius to Kelvin.

Open Ended

What's the coldness thing you can think of?

Open Ended

What's the hottest thing you can think of?

Death Valley is one of the hottest places on earth. It is located in California, USA. Temperatures can go up to 54 ^oC.

CREDIT: ALEXANDER HAFEMANN/GETTY IMAGES

One of the coldest places on earth is Dome Fuji. It is a dessert located in Antarctica. Temperatures reach about -92 ^oC.

CREDIT: Atsuhiro Muto

What is temperature?

Temperature is defined as the degree of hotness or coldness of a body.

The SI unit for temperature is Kelvin (K) however it is also common in science to express temperature in degrees Celsius (^oC). 

Measuring temperature

We use a thermometer to measure the temperature of a body.

Reading a thermometer

• Find out the smallest division of the thermometer.

• Position yourself so you can read at eye level.

• Take the reading at the meniscus.

How to covert degrees Celsius to Kelvin

To convert from degrees Celsius to Kelvin we add 273.

Temperature in Kelvin = Temperature in degrees + 273

Example: Convert 30 ^oC to K

T_{k = temperature in degrees Celsius + 273}

T_{k = 30 + 273}

T_{k = 303 K}

Example: Convert -10 ^oC to K

T_{k = temperature in degrees Celsius + 273}

T_{k = -10 + 273}

T_{k = 263 K}

How to covert Kelvin to degrees Celsius

To convert from Kelvin to degrees we minus 273.

Temperature in degrees = Temperature in Kelvin - 273

Example: Convert 373 K to ^oC

T_{c = temperature in Kelvin - 273}

T_{c =} 373 - 273

T_{c =} 100 ^oC

Example: Convert 170 K to ^oC

T_{c = temperature in Kelvin - 273}

T_{c =} 170 - 273

T_{c =} -130 ^oC

Multiple Choice

Which of the following best defines temperature.

• the amount of heat of a body.

• the degree of coldness of a body.

• the degree of hotness or coldness of a body.

Multiple Choice

The boiling point of water is?

• 100 ^oC

• 10 ^oC

• 0 ^oC

Multiple Choice

The freezing point of water is?

• 100 ^oC

• 10 ^oC

• 0 ^oC

Multiple Choice

Which of the position in the image shows the correct way of reading the thermometer?

• A

• B

• C

Multiple Choice

Convert 20.5 ^oC to K

• 280 K

• 295 K

• 290.5 K

Multiple Choice

Convert -5 ^oC to K

• 268 K

• 286 K

• 278 K

Multiple Choice

Convert 305 K to ^oC

• 30 ^oC

• 578 ^oC

• 32 ^oC

Multiple Choice

Convert 100 K to ^oC

• 170 ^oC

• -173 ^oC

• 173 ^oC