Flashcards in Part 1 Deck (31)
what is the equation for pressure difference?
pressure difference= height x density x g(10)
what is pressure measured in?
what is g?
g is the acceleration due to gravity (10)
what is the relationship between pressure at a point in a gas or a liquid?
in gases and liquids (at rest) the pressure at any point acts/ exerts equally in all directions
what is Boyle's law?
boyle's law states that at a constant temperature for a fixed mass, the absolute pressure and the volume of a gas are inversely proportional. When volume is high, pressure is low. When pressure is high, volume is low
what is the equation for Boyle's law?
what has to be constant for boyle's law to apply?
the number of molecules and the temperature
what properties do molecules in a gas have?
molecules in a gas have a random motion and they exert a force and hence a pressure on the walls of a container
why is there an absolute zero of temperature?
heat is energy and 0K is the point atoms no longer have any energy (they are frozen)
what is absolute zero?
-273°C or 0K
how can you convert from kelvin to °?
to convert from kelvin to ° simply subtract 273. To convert from ° to kelvin simply add 273
describe the kelvin scale of temperature
0K or -273° is practically the beginning of the kelvin scale.
what happens if you increase the temperature of something?
if you increase the temperature of something, you increase the energy levels in it. The molecules in it will then have more kinetic energy- this means they will be travelling faster
what is the relationship between pressure and kelvin temperature for gas in a sealed container (at constant volume)?
the pressure of a given amount of gas held at constant volume is directly proportional to the kelvin temperature. As the pressure goes up, so does the temperature and vice-versa
what is the equation for weight?
mass x g
what is mass?
the amount of physical matter that makes up an object. It is fixed therefore would be the same anywhere in the universe
what is weight?
weight shows how the mass is pulled by the force of gravity (g). The strength of g depends on where you are in the universe
what is weight measured in?
what is the equation for GPE?
mass x height x g
what is the equation for kinetic energy?
1/2 x mass x velocity2
how does conservation energy create a link between GPE, KE and work?
GPE is associated with an objects mass and its position. It is equal to the work one must do to lift an object some distance against a gravitational force. If an object falls, it gives up its GPE. The gravitational force does work on it, and speeds it up. Its GPE is converted into KE
what is the equation linking KE and GPE?
kinetic energy gained= GPE lost
what is power?
power is the measurement of how quickly work can be done/ energy can be transferred. A more powerful person can do the same amount of work in a shorter time
what is the equation for power?
power= work done/ time taken
how do you plot a distance-time graph?
distance must be on the y axis, time must be on the x axis. Simply mark the distance travelled at every chosen point eg. every second
how do you interpret a distance-time graph?
- horizontal line means the object is stationary
- diagonal line upwards means the object is moving forwards (the steeper the line the faster)
- diagonal line downwards means the object is moving backwards/towards the start
- curved lines upwards or downwards mean acceleration or deceleration
what is the equation for acceleration?
acceleration= change in velocity/ time taken
how do you plot a velocity-time graph?
velocity on y axis, time on x axis
how do you interpret velocity-time graphs?
- diagonal line upwards= acceleration
- diagonal line downwards= deceleration
- horizontal line= constant speed
- the stepper the line= the more acceleration/ deceleration