Science : Thermal energy and work

Question 1

When multiplying and dividing with significant digits…

Answer 1

…our final answer must include the least number of significant digits gone into the calculations.

Question 2

When adding and subtracting significant digits…

Answer 2

…the final answer must include the least number of decimal places that have gone into the calculation.

Question 3

Define a steam engine.

Answer 3

Any machine that generates steam and coverts the pressure from the steam into mechanical motion.

Question 4

What is the phlogiston theory?

Answer 4

When substances burned, they contained an invisible fluid called phlogiston. Believed that phlogiston flowed out of an object when it is burned.

Question 5

When was the phlogiston theory popular?

Answer 5

Early 1700’s.

Question 6

What is the caloric theory?

Answer 6

• Proposed that caloric (heat) was a massless fluid found in all substances.
• Caloric could not be created or destroyed but could flow from one substance to another.
• Caloric always flowed from warmer objects to cooler objects

Question 7

Define caloric.

Answer 7

Relating to heat.

Question 8

When was the caloric theory popular?

Answer 8

Late 1700’s.

Question 9

Define work.

Answer 9

• The transfer of mechanical energy from one object to another.
• Work is a form of energy.

Question 10

Define kinetic energy.

Answer 10

The energy an object has due to its motion.

Question 11

What is the kinetic-Molecular theory?

Answer 11

All matter is made up of atoms and molecules that are always moving. These particles hold kinetic energy and more.

Question 12

What is thermal energy?

Answer 12

Heat.

Question 13

Define heat.

Answer 13

The transfer of thermal energy from one object to another.

Question 14

Define specific heat capacity.

Answer 14

The amount of energy required to raise the temperature of a unit of mass of a substance by one 1 degree.

Question 15

Define temperature.

Answer 15

• Degree of hotness or coldness of an object.
• Mesure of thermal energy in a substance.

Question 16

Define thermodynamics.

Answer 16

Deals with forces & motion involving heat, transfer of thermal energy.

Question 17

What are the laws of thermodynamics?

Answer 17

First - Energy cannot be created or destroyed,
but can be transformed from one form
to another or transferred from one
object to another.

Second -
It is not possible for any process to
remove thermal energy from an
energy source & convert it entirely
to work

Second (plain language)
- No process can be 100% efficient
- Thermal energy always spontaneously flows
from an object at a higher temperature to an
object at a lower temperature
- Some energy will always remain in the form
of thermal energy

Question 18

Define combustion.

Answer 18

Series of chemical reactions that generate heat, reacts rapidly with oxygen and gives off heat.

Question 19

Define force.

Answer 19

A push or a pull in any direction.

Question 20

Define the law of conservation of energy.

Answer 20

Energy cannot be created or destroyed, but it can be converted from one form to another