Particles

Question 1

Density equation

Answer 1

density (g/cm3, kg/cm3) = mass (kg, g) / volume (cm3)

Question 2

Density definition

Answer 2

Measure of how compact substance is

Determined whether an object will sink or float

Question 3

Finding density of a liquid method

Answer 3

Measure mass of empty measuring cylinder using mass balance
Measure mass of cylinder with liquid in it
Measure volume of liquid using measuring cylinder
Find density using formula

Question 4

Finding density of an irregular solid object method

Answer 4

Measure mass of object using mass balance
Fill eureka can of liquid with known density e.g. water
Place measuring cylinder underneath spout of eureka can
Place object inside of eureka can
If object floats, use finger to submerge object but don’t put finger under water
Continue until no more water spills out
Measure volume of spilt water using measuring cylinder
Find density by using formula

Question 5

Solid state particles kinetic theory

Answer 5

Strong forces of attraction holding particles close together
Fixed regular arrangement
Not much energy so particles only vibrate

Question 6

Liquid state particles kinetic energy

Answer 6

Forces of attraction between particles are weaker
Particles close together but can move past each other
Irregular arrangement
More energy than solid particles
Move in random directions at low speeds

Question 7

Gas state particles kinetic theory

Answer 7

Almost no forces of attraction between particles
Particles have more kinetic energy than liquid particles
Free to move
Move in random directions at high speeds

Question 8

Cause of state changes

Answer 8

Extra energy in kinetic energy stores, making particles move faster
Overcome forces of attraction between particles
or
Particles slow down enough that forces of attraction overcome their movement

Question 9

Specific heat capacity rules

Answer 9

Heating a substance increases energy in thermal energy stores
Some materials needs more energy to increase thermal energy stores
They also stay warm longer and release more energy

Question 10

Specific heat capacity definition

Answer 10

Energy required to raise the temperature of 1kg if a substance by 1°C

Question 11

Specific heat capacity formula

Answer 11

Change in thermal energy = mass (kg) x specific heat capacity (J/kg°C) x temperature change (°C)

Question 12

Specific heat capacity of water practical

Answer 12

Use mass balance to find mass of insulating container without and with water (finds mass of water)
Place immersion heater attached to joulemeter and power supply and thermometer into water
Measure temperature of water and turn on power
Stop when temperature has increased
Record temperature change and energy on joulemeter
Rearrange equation to find specific heat capacity

Question 13

Specific latent heat definition

Answer 13

Energy required to change the state of 1kg of a substance without changing its temperature (for heating)
Energy released by a change in state (for cooling)

Question 14

Specific latent heat formula

Answer 14

Thermal energy (J) = mass (kg) x specific latent heat (J/kg)

Question 15

How gas pressure is created

Answer 15

Gas particles collide with each other or other things
This exerts a force
Outward gas pressure = total force exerted by all particles on area of container walls

Question 16

Factors affecting gas pressure

Answer 16

Temperature

Volume

Question 17

Pressure and volume formula

Answer 17

P1 x V1 = P2 x V2

Question 18

Absolute zero definition

Answer 18

When particles have little energy in their kinetic energy stores as possible
-273°C / 0 kelvin

Question 19

Kelvin in comparison to Celsius

Answer 19

°C +273

Question 20

Why changes in pressure can cause changes in volume

Answer 20

Changes in pressure change the balance between inward and outward pressure of an object, so the volume changes accordingly

Question 21

How to change internal gas pressure

Answer 21

Heating

Cooling

Question 22

How to change external gas pressure

Answer 22

Changing altitude

Pushing a syringe filled with gas hard

Question 23

Why doing work on gas increases its temperature

Answer 23

Gas exerts pressure (thus a force) on an object
Pushing object down has to be done against the pressure
This transfer energy to kinetic energy stores of gas, increasing internal energy and temperature

Question 24

What is needed for something to stretch

Answer 24

2 forces acting on it

Question 25

Elastically distorted definition

Answer 25

When an object can go back to its original shape and length after force has been removed

Question 26

Inelastically distorted definition

Answer 26

If an object doesn’t return to its original shape and length after force has been removed

Question 27

Elastic limit definition

Answer 27

Point where an object stops becoming elastically distorted and becomes inelastically distorted

Question 28

Where energy goes to an elastically distorted object

Answer 28

All energy goes to elastic potential energy store

Question 29

Force and extension formula

Answer 29

Force = spring constant (N/m) x extension (m)

extension can also be compression

Question 30

Spring constant factor

Answer 30

Material of object

Stiffer object = greater spring constant

Question 31

Work done and elasticity formula

Answer 31

Energy transferred in stretching = 1/2 x spring constant(N/m) x extension^2(m^2)

Question 32

Pressure and force formula

Answer 32

Pressure (Pa) = force (N) / surface area (m^2)

Question 33

Fluid pressure definition

Answer 33

Pressure caused by collisions of gas or liquid particles on a given surface
Force exerted is always at right angles to any surface in contact with the fluid

Question 34

Pressure exerted by fluid factors

Answer 34

Area the force is being exerted on
Properties of fluid
Surrounding atmospheric pressure
Depth 
Density

Question 35

Pressure due to column of liquid formula

Answer 35

Pressure = depth (m) x density of liquid (kg/m^3) x gravitational field strength (N/kg)