Science: Energy

Question 1

In physics, what is WORK DONE

Answer 1

Work done is the energy transferred when a force is used to move an object a certain distance

Question 2

What measurement is WORK measured in ?

Answer 2

JOULES

Question 3

Formula used to calculate WORK DONE (in Joules)?

Answer 3

work done (J) = force (N) × distance moved (m)

Question 4

What is a force multiplier?

Answer 4

A force multiplier uses a smaller input force (what you apply) to to generate a larger output force (what is created)

Question 5

Give an example of a FORCE MULTIPLIER

Answer 5

A lever is an example of a force multiplier, a longer lever will require a less input force than a shorter lever to produce the same output force

Question 6

What happens If you increase the distance of the force applied, from the pivot,

Answer 6

less input force is needed to be used for the same output force as before

Question 7

What is THERMAL ENERGY + what measurement is it measured in?

Answer 7

The thermal energy of a substance depends on the individual energy of all of the particles, it is measured in Joules (J)

Question 8

Do faster moving particulars have MORE or LESS thermal energy?

Answer 8

MORE

Question 9

When particles are heated they begin to move MORE or LESS quickly

Answer 9

MORE

Question 10

The energy needed to increase the temperature of a substance depends on:

Answer 10

•the mass of the substance
•what the substance is made of
•how much you want to increase the temperature by

Question 11

What is RADIATION? + give an example

Answer 11

Radiation is a method of transferring energy without the need for particles

An example of radiation is thermal energy being transferred from the Sun to us through space
(where there are no particles)

This type of radiation is known as infrared radiation, it is a type of wave just like light

Question 12

The hotter an object is the MORE or LESS infrared radiation it will emit (give out)

Answer 12

MORE

Question 13

The amount of radiation emitted and absorbed depends on:

Answer 13

the surface of the object

Darker matte surfaces absorb and emit more infrared radiation

Shiny and smooth surfaces absorb and emit less infrared radiation, instead reflecting this

Question 14

What is CONDUCTION

Answer 14

Conduction is the transfer of thermal energy by the vibration of particles

Every time particles collide they transfer thermal energy

Question 15

Are metals GOOD or BAD thermal CONDUCTORS? + why?

Answer 15

GOOD

As they contain electrons which are free to move

Question 16

In conduction, thermal energy is transferred from where to where?

Answer 16

From an area with a high thermal energy store (high temperature) to an area where there is a low thermal energy store (low temperature)

Question 17

Are gases and liquids goofd CONDUCTORS?

Answer 17

NO - as their particles are spread out and so do not collide often, we call these insulators

Question 18

What is CONVECTION?

Answer 18

Convection is the transfer of thermal energy in a liquid or a gas, it cannot happen without particles

Question 19

Describe CONVECTION CURRENT

Answer 19

As the particles near the heat source are heated they spread out and become less dense, this means that they will rise

More dense particles will take their place at the bottom nearest the heat source creating a constant flow of particles

This is known as a convection current

Question 20

Can CONVECTION happen in solids?

Answer 20

Convection cannot happen in a solid as the particles cannot flow, they can only move around a fixed point