Physics y9

Name 4 vectors

acceleration

Displacement

Forces

Velocity

Name 3 scalars

Energy

Mass

Speed

Reason for reaction force

Atoms can't blend together so they level out with the forces

Newton's 1st law in bullet points

Stationary object will remain stationary

Object at a constant speed will remain at a constant speed unless acted upon by unbalanced forces

What happens if you 'let go' of centripetal forces

leave in a straight line

The faster something travels in a circle,

Centripetal forces increase

Vectors and scalars in centripetal forces

Changing

Constant

What should force lines have

Arrowheads

What is the upward force for solids

Reaction

What is the upward force for liquids

Upthrust

If it's elastic, it returns to its

Original shape

If it's inelastic,

It doesn't return to its original shape

Enough force pulling on a spring, it reaches its

Elastic limit and cannot return

On hooke's law graph, the x and y axis

extension, force

Hooke's Law

Force applied is directly proportional to extension

Investigating springs experiment

Set up clamp stand, ruler, spring, weights

Measure and write original length

Hang mass and record new length

Add more masses

repeat on different springs and average

What is spring constant

Measure of the force needed to extend the spring by 1 metre / stiffness

On an extension by force graph, the steeper the line,

Higher k, stifferr

What is displacement in waves

How far from the equilibrium the wave oscillated

Transverse waves oscillations are ... to direction of energy transfer

Perpendicular

Longitudinal waves oscillations are ... to direction of energy transfer

Parallel

What is a wavelength in longitudinal waves

Point of compression to compression

Transverse high and lows are

Crest, trough

Longitudinal high and lows are

Compression, rarefraction

Wavelength

The distance between two corresponding parts of a wave

Compression in waves

Region where particles are closest together

Rarefraction waves

Region where particles are furthest apart

Radio waves use

Communication

Radio waves danger

none

Microwaves uses

Cooking, satellite

Microwaves danger

Cell heating

Infrared use

Short communications

Infrared danger

Skin burns

Visible use

Photos

Visible danger

None

UV use

Detecting money forgeries

UV dangers

Sunlight burns

X-rays use

X-ray

X-rays danger

Cancer

Gamma rays use

Sterilise equiptment

Gamma rays dangers

Cancer

Differences in EM spectrum (2)

Frequency, wavelength

Similarities in EM spectrum (3)

Speed, transverse, travel in vacuum

Which EM spectrum can we detect

IR, visible light

Which EM spectrum can penetrate the atmosphere

Visible light and radio waves

Which EM spectrum can partially penetrate the atmosphere

X rays, gamma, UV, IR, microwaves

Green light through red filter

Black

Red through blue filter

Black

Solid arrangement

Structured

Liquid arrangement

Touching, no empty spaces

Gas arrangement

Sparse, random

Volume in solid

Fixed

Volume in liquid

Fixed

Volume in gas

Not fixed

Shape of solid

Fixed

Shape of liquid

Not fixed

Shape of gas

Not fixed

Motion of solid

Vibration in place

Motion of liquid

slide past each other

Motion of gas

Rapid, random

Parallax error

Misread of the numbers

Misread of the numbers error

Parallax

Measure mass using a

Balance

Measure force/weight using

Scales

Zero error

Balance not set to 0

Balance not set to 0 error name

Zero error

Why does pressure act on a solid in water

Surrounding water molecules collide with it

With the constant pressure at the bottom of all containers , water...

Flows at the same depth

Water at the top of the container has ... pressure, least ... and therefore ...

Least, force, distance

More depth, .... pressure

More

What causes upthrust

the difference in pressure above and below the object

Frequency

Number of complete oscillations per second

Upthrust \=

Weight of the displaced water

What must an object do to float

Displace enough water

all 8 energy stores

Magnetic

Elastic

Nuclear

Thermal

Gravitational potential

Electrostatic

Chemical

Kinetic

All 4 energy transfers

Heating

Electricity

Radiation (waves)

Mechanically

Conservation of energy

Energy cannot be created or destroyed but it can be transfered

Burning a candle stores and transfer

Chemical Heating Thermal

Rubbing hands stores and transfer

Kinetic mechanically/heating thermal

Sled down a hill stores and transfer

Gravitational mechanically kinetic

Releasing catapult stores and transfer

Elastic potential mechanically kinetic

Battery by torch stores and transfer

Chemical electricity thermal

Battery by lifting load stores and transfer

Chemical electric gravitational

Dropping a ball energy stores

GPE → KE

Dropping a ball equations

mgh → 0.5mv2

V=2gh

If the speed x2, the KE x ?

4

If the speed x3, the KE x ?

9

Efficiency of a bouncing ball experiment (6)

Hold ball at 1m

Drop the ball

Measure 1st bounce

Efficiency equations

Repeat and average

Different balls

6 marker on floating

The floating boat has weight and upthrust; they are balanced. The loaded boat has greater weight and needs greater upthrust to displace more water because the weight of the displaced water is equal to the upthrust

Direction is changing, why is velocity

Velocity is magnitude and direction, direction is changing therefore it's accelerating

Moving in a circle, what is the resultant force

Centripetal

What is the third difference between longitudinal and transverse waves

Transverse have a point of equilibrium

Radio waves are transverse or longitudinal

Transverse

Sound waves are transverse or longitudinal

longitudinal

Examples of longitudinal waves (3)

Sound, seismic P, ultrasound

Examples of transverse waves (3)

Electromagnetic, seismic S, water ripples

Gravity is

The force of attraction between two objects

Acceleration is

rate of change of velocity

Orbits are

The curved path of one celestial object r spacecraft around another celestial object

instantaneous velocity

the speed and direction of an object at a particular instant