Materials and Density yr9 end of year revision 2025 Flashcards
(20 cards)
What is a linear and non-linear relationship
between two quantities?
-IF the line is straight it is a line of best fit then we call this a linear relationship.
-IF the line is not straight then it is non linear
What is meant by a directly proportional
relationship between two quantities?
If a graph is plotted and the line of best fit goes straight through the origin then it is directly proportional between two quantities
What is the spring constant?
-The amount of force needed to to stretch or compress a material by 1m
-The unit is N/m
How do you determine spring constant from
a force extension graph?
The spring Constance is the gradient of the straight part of a force extension graph.
This is where the force is on the x-axis and the spring Constance is on the y-axis.
What is the relationship between force,
spring constant, and extension?
-Force = spring constant × extension
-F = ke
-Force (Newtons, N), Spring constant (Newtons per metre, N/m), Extension (metres, 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)
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 return to its original length when the force is
-removed if it hasn’t passed the limit of proportionality.
What is the relationship between mass,
volume, and density?
Density =mass / volume
ρ =m/V
Density (kilograms per metre3, kg/m3),
,Mass (kilograms, kg),
Volume (metres3, m3)
How do you measure the volume of regular
shaped objects accurately?
-It can be found by multiplying the length, width and height together.
-Each dimension can be found accurately by repeating the measurement with a ruler in different places along each side ( and then averaging).
- Make sure the ruler is at 90 degrees to the edge.
How do you measure the mass of
an object accurately?
Place a digital balance on a flat surface and zero it (press the tare button) before placing the object on it.
What do we mean by “uncertainty”
in a measurement?
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.
-The range can be
found by taking the minimum value from the maximum.
How can particle arrangement be
used to explain the differences in
density between solids, liquids, and
gasses?
- same volume of a substance in its solid, liquid and gaseous forms
- This means that there is much
more space between the particles in a gas than in a liquid or solid. - same volume = much less mass of gas.
- density of
a gas is less (since mass is less for an equal volume) than a solid or liquid.
Why does density change when a
substance changes state?
-When a substance changes state the same mass of substance will now occupy a different volume.
-Since density = mass/volume it follows that density will change since volume changes.
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.
On a force extension graph where is the limit
of proportionality?
The limit of proportionality on this graph is where the line stops being straight. It is the point at
which it begins to curve.
How do you carry out a force extension
experiment accurately?
Set up a clamp stand with a spring.
Clamp a ruler making sure it is vertical with a set square.
Make sure the zero of the ruler is at the bottom of the spring.
Add masses and record the extension of the
ruler each time.
Make sure to measure the extension at eye-level.
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 is the particle model of
matter?
