Material and Density (Chapter P6) Flashcards
What is a linear relationship on a graph
If the line of best fit is straight then we say that there is a linear relationship between the two quantities on the x and y axes.
What is a non-linear relationship on a graph
If the line is not straight then it is non-linear.
What does a directly proportional relationship between 2 quantities look like on a graph
If the line of best fit is straight and goes through the origin then there is a directly proportional relationship between the two quantities.
What is the spring constant?
What units is it measured in?
The spring constant is the amount of force needed to stretch (or compress) a material by 1 m.
Its unit is N/m.
How do you determine spring constant from a force extension graph?
The spring constant is the gradient of a force-extension graph when force is on the y-axis and extension on the x-axis.
What is the equation for force
Force = spring constant x entension (m)
What is Hooke’s law?
The extension of a material is directly proportional to the force applied up to the limit of proportionality (elastic limit)
On a force extension graph where is the limit of proportionality?
It is where the line stops being straight, the point at which it begins to curve.
What is meant by elastic deformation?
An object which is stretched (or compressed) will return to its original length when the force is removed if it hasn’t passed the limit of proportionality.
What is meant by inelastic deformation?
An object which is stretched (or compressed) will not return to its original length when the force is removed if it has passed the limit of proportionality. There will be permanent deformation.
What is the equation for density
Density = mass / volume
How do you measure the volume of irregular shaped objects accurately?
Add a specific amount of water into a measuring cylinder. Add the irregular object to the water and measure the new combined volume of the water and object. Subtract the volume of the water to get the volume of the object.
OR
Fill a Eureka can to the spout with water. Add your irregular object to the water and allow the water to run into a measuring cylinder. The volume of the water displaced is the volume of the object.
What do we mean by “uncertainty” in a measurement?
Uncertainty is the range of values in which we expect the true value of a measurement to lie.
When a measurement is repeated, what is the uncertainty in that measurement?
When measurements are repeated the uncertainty in the measurement is 1⁄2 of the range.
What do we mean by the resolution of a measuring instrument?
The resolution of a measuring instrument is the smallest change that can be read from that instrument e.g. 1 mm on a ruler, or 1° on a protractor.
What is the equation for density
Density = mass / volume
What is the equation for mass
mass = density x volume
What is the equation for volume
volume = mass / density
How do you find the volume of a small irregular solid
Place it in a measuring cylinder which has water in it and then see how much the water level rises
How do you find the density of a liquid
You measure out a certain volume of the liquid and then weigh it.
You take the weight of the container and take it away from the weight of the container ad liquid
What is the conservation of mass
When a substance changes state, the number of particles stays the same. So the mass is the same.
What is latent heat
It is the energy transferred to a substance when it changes state
What is internal heat
The energy stored by the particles of a substance
What decides the state of a substance
The strength of the forces of attraction between the particles
What happens when a substances temperature rises
the kinetic energy of its particles increases
What happens when a substance melts or boils
The potential energy of its particles increases
What is the specific latent heat of fusion
It is the energy needed to change the state of 1 kg of a substance from solid to liquid
What is the equation for specific latent heat of fusion
= energy / mass
What is the specific latent heat of vaporisation
It is the energy needed to change that state of 1 kg of a substance from liquid to vapour
what is the equation for specific latent heat of vaporisation
= energy / mass
What is the units for specific latent heat
J/kg
