Q4: Lesson 4 (Heat & Efficiency)

Question 1

What is an energy guide?

Answer 1

Energy guide are labels found on an appliance, it displays the efficiency rating of the certain appliance. Higher efficiency rating = Less energy spent, meaning you save electricity for the appliance to do its job.

Question 2

Define “Efficiency”

Answer 2

The ratio of how much energy/power we get from the appliance VS the amount of energy we put into the appliance

Question 3

What is the Unit for Efficiency

a.) Lumigas (Lg)
b.) Electrowatts (Ew)
c.) Jouleflows (Jf)
d.) none of the above

Answer 3

None of the above, there is no unit of measurement for efficiency.

Question 4

True or False, if false indicate the certain word that’s wrong and replace with the correct word.

Efficiency is expressable from one to 500

Answer 4

False, efficiency is only expressable from 0-1

Question 5

Explain to me how efficiency is only expressable from 0-1

Answer 5

It works like this:

if efficiency is = 0, there is no efficiency at all.

if efficiency = 0.1, then the efficiency is 10%, and so on..

Question 6

Why is 100% efficiency known to be impossible for machines?

Answer 6

It is impossible as some of the heat that’s being transferred gets converted into different types of energy that are not intended for the purpose of the machine

Question 7

What does efficiency depend on?

Answer 7

it depends on the temperature

Question 8

What does higher efficiency equal to?

Answer 8

More mechanical work done

Question 9

Explain how the geothermal powerplant works

Answer 9

1. The powerplant pumps hot water from underground
2. The steam of the hot water turns the turbine
3. The turbine makes the generator turn, which produces electricity
4. The electricity is transported from the generator to the power grid

Question 10

Where does the hot water from underground come from?

Answer 10

The volcano’s magma heats the water from an underground water reservoir.

Question 11

Explain how the four-stroke engine works.

Answer 11

1. Air and fuel go inside the cylinder and compresses them
2. Compression of Air and fuel
3. The gas would ignite, producing heat due to the compression of air and fuel.
4. The piston goes down, then up, pushing out the burned mixture through the exhaust valve.

Question 13

define heat

Answer 13

energy being transfered from one body to another

Question 14

What can heat only flow in?

Answer 14

Object with higher temp to lower temp only

Question 15

ways heat can be transfered

Answer 15

Conduction, Convection
or Radiation

Question 16

explain “THERMAL EQUILIBRIUM AND
ZEROTH LAW”

Answer 16

when heat transfer occurs, it will keep on transfering until they both have an equal temperature

Question 17

what does the law of conservation of energy state?

Answer 17

energy can neither be created nor destroyed

Question 18

what is renewable energy

Answer 18

renewable energy is an energy that comes from sources that are replaced easily

Question 19

what is non renewable energy

Answer 19

non renewable energy is energy that isn’t replaced so easily