Chapter 3

Question 1

What is energy

Answer 1

• The capacity to do work or provoke a change.
• hard to measure directly
• usually study its effects
• a change of state is accomplished through a change in energy

Question 2

what are the units for energy. explain. (earth)

Answer 2

1 J corresponds to the energy needed
to lift an object weighing 1N (newton)
a distance of 1m (meters)

On Earth, an object weighing 1N has
a mass of about 100g

Question 3

what are the forms of energy

Answer 3

chemical
electrical
mechanical
thermal
radiation
elastic
wind
sound
hydraulic
nuclear

Question 4

what is transformation of energy

Answer 4

transformation of energy goes from one type of energy to another.g

Question 5

give an example of transformation of energy referring to the sun

Answer 5

Sun surface (nuclear fusion)
travels to earth as Sunlight
(Radiant) and heats up the
asphalt (thermal)

Question 6

what is energy transfer

Answer 6

movement of energy from one place to another

Question 7

give an example of energy transfer referring to a fire and a kettle

Answer 7

Heat from the fire transfers
to the kettle, the man and
the kitty

Question 8

what is the law of conservation of energy

Answer 8

Energy can be neither created nor destroyed,
only transferred or transformed. The total
amount of energy in a closed system
remains constant.

Question 9

what is energy efficiency

Answer 9

Energy efficiency refers to the percentage of
useful energy in relation to the total energy
being used in the system.

Question 10

what is thermal energy1

Answer 10

-Thermal Energy refers to the energy contained in a substance (How excited the particles are)
-The greater the mass the greater the thermal energy
-Heat is the transfer of Thermal Energy.
-Measured in joules or kilojoules

Question 11

what is heat

Answer 11

-The transfer of thermal energy
between two environments with
different temperatures
-Always goes from warmer to colder
environment
-Depends on both the agitation of
particles and the mass of the
substance

Question 12

what is temperature

Answer 12

-Measured only in degree of
agitation of the particles of
the substance at a given point
in time

Question 13

what is the symbol of heat in J

Answer 13

Q

Question 14

what is delta E

Answer 14

the change in thermal energy

Question 15

what does the change in temperature depend on

Answer 15

the specific heat of the substance being heated or cooled

Question 16

what is specific heat capacity

Answer 16

-This is a different value of every substance
making it a Characteristic Property.
-The amount of thermal energy needed to heat
1 g of a substance 1 degree Celsius
-This value is represented by the letter c.
(J/goC)

Question 17

what is kinetic energy

Answer 17

the energy an object possesses due to its motion

Question 18

what is potential energy

Answer 18

the energy reserve of an object based on the mass, height, and the gravitational field

Question 19

what is mechanical energy

Answer 19

potential energy added with kinetic energy

Question 20

what is motion

Answer 20

changing location as a function of time