Unit 1: Energy Transformation

Question 1

What is energy?

Answer 1

energy is the ability to do something, the ability to change something

Question 2

How many kinds of energy are there?

Answer 2

Kinetic energy and protentional energy

Question 3

What is the law of conservation of energy?

Answer 3

within a closed and isolated system, the total amount of energy is constant. It can’t be created or destroyed. It can only be transferred or transformed from one object to another.

Question 4

What is the definition of Mechanical Kinetic Energy?

Answer 4

the energy an object has in motion.

Question 5

What determines how much kinetic energy an object has?

Answer 5

mass and speed

Question 6

What are quantities?

Answer 6

things that you measure

Question 7

What are symbols?

Answer 7

the letters we use to represent the quantities

Question 8

What are units?

Answer 8

what the quantities are measured in

Question 9

What is the formula for Kinetic energy?

Answer 9

Ek = 1/2mv^2

Question 10

What is gravitational potential energy?

Answer 10

the energy stored in an object due to its position above a reference point such as the floor, ground, etc.

Question 11

What determines how much potential energy an object has?

Answer 11

mass, height above the reference point and its acceleration due to gravity

Question 12

What is the formula for potential energy?

Answer 12

Eg = mgh

Question 13

What is the acceleration due to gravity on earth?

Answer 13

9.80 m/s^2

Question 14

What happens when there is no friction?

Answer 14

the total amount of energy remains constant. It is simply transformed back and forth between potential and kinetic energy. This creates the ideal isolated system.

Question 15

What happens when there is friction?

Answer 15

the total amount of energy still remains constant but whatever is being converted between potential and kinetic, some of it converts to thermal energy and becomes “lost”.

Question 16

Why can we conclude that the same of potential and kinetic energy at multiple points is the same?

Answer 16

If the total amount of mechanical energy in a system is constant, that means we can compare any 2 points and the sum of the potential and kinetic energy will be the same.

Question 17

What are the formulas for mechanical energy?

Answer 17

Egi + Eki = Egf +Ekf

Ek + Eg = Em
1/2mv^2 + mgh = Em

Question 18

What is the definition of thermal energy?

Answer 18

the energy stored in matter, composed of the kinetic and potential energies of molecules as they move.

Question 19

How is thermal energy and temperature related?

Answer 19

a cup of warm water and a bathtub of warm water can have the same temperature but different amount of thermal energy. The bathtub would have more total energy. Therefore a bathtub full of cold water can still have more thermal energy than a cup of hot water,

Question 20

What is the definition of temperature?

Answer 20

the measure of hte average thermal energy per molecule

Question 21

What is the symbol used to measure temperature?

Answer 21

T

Question 22

What was the first standard scale to measure temperature?

Answer 22

Fahrenheit

Question 23

Who created the Fahrenheit system?

Answer 23

Daniel Fahrenheit a german physicist in 1714.

Question 24

What was the freezing, room temp and boiling points of fahrenheit?

Answer 24

water freezes at 32, boils at 212 and room temperature is 68-70.

Question 25

Who created the Celsius measurement system of temperature?

Answer 25

Anders Calsuis a swedish astronomer is 1741. Also called Centrigrade which means 100 divisions

Question 26

What are the freezing, room temp and boiling points in Celsuis?

Answer 26

water freezes at 0, boils at 100 and room temp is 20-21. Originally set up reversed though after founders death is was changed.

Question 27

Who created Kelvin?

Answer 27

A british mathematician adn Physicist lord Kelvin (william thomson) in 1848.

Question 28

What is absolute zero?

Answer 28

as an objects temperature drops the kinetic energy of the molecules also drops. At -273.15C all motion of molecules stops, it is known as the lowest possible temperature. The Kelvin scales calls this absolute zero.

Question 29

What are the freezing points, room temp and boiling in Kelvin?

Answer 29

water freezes at 273, boils at 373 and room temp is 293-294.

Question 30

What is the difference between heat and thermal energy?

Answer 30

thermal energy is what every substance has. Heat is the energy that transfers from a hotter object to a coller one naturally.

Question 31

is it possible to transer thermal energy from a cooler object to a hotter one?

Answer 31

yes, a refrigerator or air conditioner.

Question 32

What does the amount of heat energy needed to raise a temperature of an object depend on?

Answer 32

mass, material(specific heat capacity), desired temperature

Question 33

What is a calorie?

Answer 33

raising 1kg of water by 1 degree

Question 34

What is the formula for heat energy?

Answer 34

Q = MC triangle T

Question 35

Why is the specific heat of water height relevant to our lives

Answer 35

to raise water equires a very large transfer of energy. Water gives offa lot of energy as it cools so large bodies of water moderate climates and keep the earth as a whole from heating or cooling too much