Particles And Forces

Question 1

Density

Answer 1

Is the amount of mass per unit volume

Question 2

Density Equation

Answer 2

Density(kg/m3 : g/cm3 = mass (kg : g) / volume (m3 : cm3)

Question 3

Change of states

Answer 3

Solids (keep shape)
Liquid (takes shape of container)
Gas (fills shape)

Question 4

Evaporation

Answer 4

Particles in a liquid have different energies, some have enough energy to escape from the liquid and changes state to a gas

Question 5

Conservation of mass

Answer 5

• A change of state is a physical change
• when it changes state, it’s mass doesn’t change
• goes in a loop, if you reverse it you will get back to its original form and properties

Question 6

Particles motion in gases and liquids

Answer 6

The molecules of fluids are at a constant random movement

Question 7

Contact forces

Answer 7

Friction
Air resistance
Tension 
Reaction 
Thrust

Question 8

Non contact forces

Answer 8

Magnetic forces
Electrostatic forces
Gravitational forces

Question 9

Equation for moving objects

Answer 9

Force (N)= mass (Kg) x Acceleration (m/s2)

Question 10

Gravity

Answer 10

The forces between all objects

Question 11

Formula for working out what you weigh on earth
ConvErting mass to force
Hint x or / by 10

Answer 11

Weight ( N) = mass (Kg) x gravitational force (N/Kg)

Question 12

Centre of mass

Answer 12

The point at which the weight of a body acts or where the mass appears to be concentrated

Question 13

Finding the centre of mass of regular shapes

Answer 13

Use ALL the lines of symmetry

Where they cross is the centre

Question 14

Work done

Answer 14

Energy cannot be made or changed

Measured in joules

Question 15

Calculating work

Answer 15

Work (J) = force (N) x distance (s)

Question 16

Work

Answer 16

The amount of energy transformed when an object moves in the direction of the force

Question 17

Power

Answer 17

Is work done in given time

Question 18

Power equation

Answer 18

Power (W) = work done (J) / time (s)

Question 19

Deformation

Answer 19

A change in shape

Forces acting upon an object cause deformation

Question 20

Elastic deformation

Answer 20

Is reversed when when the force is removed

Question 21

Inelastic deformation

Answer 21

Is not full reversed

There is a permanent change/ loss in shape

Question 22

Hooke’s law

Answer 22

The extension of a spring is directly proportional to the force applied as long as limit of proportionality is not exceeded

Question 23

Force equation

Answer 23

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

Question 24

The Spring constant

Answer 24

The Spring constant depends on the material that you are stretching the spring, the greater the spring constant

Question 25

Elastic potential energy

Answer 25

Anything stretched has elastic energy, like rubber band

Question 26

Hooke’s law variable

Answer 26

Dependant - the measure of extension
Control - the placement of the rule and spring, same amount of weight
Independent - the weight / force applied