Temperature

By: David Garcia P.5

How is temperature commonly measured?

• Temperature is commonly measured by thermometers that may be calibrated to a variety of temperature scales.

How many degrees are between the melting point of ice and boiling point of water on the

Celsius scale? Fahrenheit scale? • Between the melting point of ice and

boiling point of water on the Celsius scale is 100 degrees (0-100). And the melting point in Fahrenheit is 180 degrees.

Why is it incorrect to say that matter contains heat?

• It is incorrect to say that matter contains heat because heat is not an internal property of matter (temperature is). Heat is just a way to change the temperature of an object... it’s a flow of energy.

In terms of differences in temperature between objects in thermal contact, in what direction

does heat flow? • The direction heat flows in includes

parallel flow, counter flow, and cross flow.

What is meant by saying that a thermometer measures its own

temperature? • When a thermometer reaches thermal

equilibrium, the temperature of the thermometer and the substance it is measuring are the same. Therefore, the thermometer is essentially measuring its own temperature.

What is thermal equilibrium?

• Thermal Equilibrium is when the temperature of a system or organism is equal to the temperature of its surroundings.

What is internal energy?

• Internal Energy is the total energy contained by a thermodynamic system.

What is the difference between a calorie and a Calorie?

• The difference between a calorie and a Calorie (upper-case) is that one of them is used in nutritional forms.

What does it mean to say that a material

has a high or low specific heat capacity?

• It means that a material with a high specific heat capacity has a high capacity for storing heat energy.

Why is the North American west coast warmer in winter months and cooler in summer months

than the east coast?

• The west coast is warmer in winter months and cooler in summer months than the east coast because the Ocean currents in the Pacific carry warmer waters from the South and another current carrying cold water also comes in from the North, both keeping the West coast in balance, while the temperatures on the East coast vary greater because of this lack of oceanic temperature control.

Which expands most for increases in temperature: solids, liquids, or

gases? • Gases expand most for increases in

temperature.

At what temperature is the density of water greatest?

• The density of water is greatest at 4 degrees Celsius.

Why do lakes and ponds freeze from the top down, rather than from the bottom

up? • The ponds freeze from top to bottom instead of

bottom up because it increases its density with cooling until it reaches 4oC (Above freezing) at that time getting cooler lowers its density. As a consequence the coldest water floats on top of the above freezing point water. The ice (when it forms) is even less dense and floats at the top of the pond on the colder and warmer water. As a consequence the water that freezes is nearest the top.

Why do shallow lakes freeze quickly in winter, and deep lakes not at all?

• Shallow lakes freeze quickly in winter and deep lakes don’t because water stores what is called latent heat. This is basically the energy required to convert water through its stages. The lack thereof of this energy is the change from liquid to solid. The smaller and shallower lakes possess less liquid water and, thus less latent energy. As a consequence they lose energy and freeze more quickly when the surrounding atmospheric and soil temperatures are below the freezing point.