Stuff Flashcards
What comes after this start in equation
Final velocity ² - initial velocity ²
2 × acceleration × distance
Whats the acceleration in free fall
10m/s
What is newtons first law
An object at rest or in motion will remain at rest or in motion unless compelled to change its state by the action of an external force
Describe the velocity of something moving in a circular orbit at a constant speed
It has a changing velocity
What is the resultant force for motion in a circle
Centripetal force which acts towards the centre of the circle
What is inertial mass
S measure of how difficult it us to change the velocity an object
Ratio of force
______________
Acceleration
What is newtons third law
states that for every action (force) in nature there is an equal and opposite reaction.
Ahat are crumple zones?
Crumple zlnes are areas of a vehicle designed to increase the time taken to change the momentum of the driver and passengers in a crash, which reduces the force involved.
What do frequency and wavelength mean?
Frequency = The number of vibrations made by a particle of the medium in one second
Wavelength =the distance between identical points of a waveform
Label the wave
Top bit is the crest
Bottom but is the trough
The difference between the middle line and the top of the wave is the amplitude
One full wave cycle is the wavelength
How to measurement speed of sound in air
A data logger can measure and record the time taken for sound to reach two microphones.
How to calculate wave speed
Count the number of waves passing a point in ten seconds then divide by ten to record frequency. Calculate the speed of the waves using: wave speed = frequency × wavelength.
All electromagnetic waves are
Transverse
Order of electromagnetic spectrum
Radio waves
Microwaves
Infrared
Visible
Ultraviolet
X rays
Gamme
How does the danger of an electromagnetic wave increase?
With frequency, the lower the frequency the safer the wave
Harmful effects
Microwave =internal heating of body cells
Infrared = skin burns
Ultraviolet = damage to surface cells and eyes leading to skin cancer and eye problems
X-rays and gamma rays = mutations or damage to cells in thr body
Usesof electromagnetic spectrum
Radio= broadcasting infomation
Microwaves= cooking
Infrared = thermal imaging
Visible light= vision , photography
X rays = medical x rays
Gamma = , the detection of cancer and its treatment
How had the model of the atom changed over time
- John Dalton published his ideas about atoms in 1803. , which he imagined as tiny spheres that could not be divided.
- Nearly 100 years later, J J Thomson carried out experiments and discovered the electron .
