Deck 1 = Physics start of year- 10/10/13

Question 1

What is energy measured in?

Answer 1

-Joules.

Question 2

Name types of energy?

Answer 2

-Chemical potential, kinetic, gravitational potential, potential, elastic potential, nuclear potential, thermal energy, electrical, radiation.

Question 3

What is energy measured in?

Answer 3

-Joules.

Question 4

Law of energy conservation?

Answer 4

-Energy can not be destroyed, During each transformation, the total amount of energy stays the same.

Question 5

What happens to GPE as you climb?

Answer 5

-It increase.

Question 6

Gravitational field strength on earth?

Answer 6

-10 newton per kilogram.

Question 7

What is the efficiency equation?

Answer 7

-Efficiency = useful power output (w) over power input (w).

Question 8

Work done =

Answer 8

-Energy transformed measured in J.

Question 9

Unit for energy efficiency?

Answer 9

-No unit, or percentage.

Question 10

What is kinetic energy measured in?

Answer 10

-J

Question 11

What is thermal energy measured in?

Answer 11

-J

Question 12

What is chemical potential measured in?

Answer 12

-J

Question 13

What is power measured in?

Answer 13

-W

Question 14

Define work?

Answer 14

-Work is done whenever a force make something move. The greater the force and the greater the distance moved, the more work is done.

Question 15

One joule=

Answer 15

-One newton meter.

Question 16

If an engine does 2000J of useful work in 2 seconds, what is its power output?

Answer 16

-1000J

Question 17

Engine does 25J of useful work for every 100J of energy supplied, what is its efficiency?

Answer 17

-0.25 or 25%

Question 18

Rearrange GPE=mgh to find H?

Answer 18

-GPE over mg = H

Question 19

Equation for Kinetic energy?

Answer 19

-KE=0.5mv2 (squared).

Question 20

The higher the temp…

Answer 20

-The faster the atoms moving.

Question 21

Absolute zero =

Answer 21

-273oC 0K this can never be reached because you need something colder to take away the thermal energy.

Question 22

When we say to things are at the same temp, this means…

Answer 22

-They do not have a thermal energy transfer.

Question 23

Standard atmospheric pressure.

Answer 23

-101325 Pa.

Question 24

When you put a hot and a cold thing together…

Answer 24

-The hot thing loses its kinetic energy and the cold thing gains Kinetic energy.

Question 25

Define Conduction?

Answer 25

-This is when thermal energy or randomized kinetic energy is transferred from one place to another due to collisions between particles. This happens more quickly in metals.

Question 26

Particles in hot objects…

Answer 26

-Vibrate with a large amplitude. large then that of liquids and gasses.

Question 27

What is convection?

Answer 27

-Liquids and gases are poor thermal conductors however they are free to circulate and they are also aloud to carry thermal energy from one place to another quickly.

Question 28

Define convection current?

Answer 28

-Liquids or gasses become less dense when they are heated making them rise. they then cool and sink. It happens in a circle, this i called a convection current.

Question 29

How can you reduce convection?

Answer 29

-By holding or trapping air in place.

Question 30

How does this happen with a fridge?

Answer 30

-Cold air sinks because it is more dense and the hot air rises. then the hot are is sucked out the fridge.

Question 31

How does conduction work?

Answer 31

-Particles vibrating with big amplitude transfer their kinetic energy to there neighbor through collisions.

Question 32

How does convection work?

Answer 32

-Heated fluids expand, becoming less dense and rising. cooler fluids do the reverse, this sets up a convection current.

Question 33

How does Radiation work?

Answer 33

-All objects emit inferred or thermal radiation. Hot objects emit more. When this energy is absorbed energy in transformed.

Question 34

How do we minimize conduction?

Answer 34

-Use insulator.

Question 35

How do we minimize radiation?

Answer 35

-Paint an object white or give it a silver reflective surface.

Question 36

How do we maximize conduction?

Answer 36

-Use a good conductor such as copper.

Question 37

How to maximize convection?

Answer 37

-Allow the fluid to move freely.

Question 38

How to maximize radiation?

Answer 38

-Paint an object black, this maximizes emissions and absorption.

Question 39

What is time measured in?

Answer 39

-Seconds (s)

Question 40

What is energy transferred measured in?

Answer 40

-J

Question 41

What is work done measured in?

Answer 41

-J

Question 42

Efficency equation?

Answer 42

-Useful power over total power input.

Question 43

Equation for power?

Answer 43

-Energy transferred (j) over time (s).

Question 44

Power Work done equation, Power =

Answer 44

-Work done over time. Wd/t.

Question 45

Power Energy equation, Power=

Answer 45

-Energy (j) over time (s).

Question 46

How to make a house more energy efficient?

Answer 46

• Loft insulation.
• Double glazing.
• For doors and windows use draft exclude.

Question 47

What is the process called when a material can only conduct in a liquid form?

Answer 47

-Electrolysis.