Waves:
Converting units:
mA → A (divide by 1000)
Random tips:
Independent variable: what you are changing
Dependent variable: what you are PHYSICALLY measuring e.g.
length, weight
Use a graph line to determine the value of n=sini/sinr because it
allows you to use all the data rather than just two points and you
can discount anomalies more easily
On graphs look for lines being directly proportional - the points
should go through the origin
With experimental design, always state ‘repeat and
calculate an average’
Megajoules to joules x 1000,000
Past exam question: investigating how temperature affects how
high a ball bounces
Independent variable: temperature change in a water bath
container
Dependent variable: height measured in m by a measuring rule that
the ball bounces
Control variables (+3): mass of the ball the same, same floor and
same force that the ball is dropped at and height ball is dropped
from
Repeats: repeat the whole experiment five times and find an
average excluding any anomalies
High-quality data: rule with small increments, use a camera and
view is slow motion
Forces:
How to investigate Hooke’s Law:
1. Hang a spring off a clamp stand
2. Measure the original length
3. Add a weight and measure the new length of spring
4. Repeat for a range of weights
5. Repeat and calculate an average
6. Plot a graph of length vs weight
7. Graph should be a straight line and pass through the origin
,At point A the limit of proportionality has been reached. And the spring
has been irreversibly damaged.
Terminal velocity:
Parachutist jumps out of the airplane
Weight acts downwards
Air resistance acts upwards
Object accelerates downwards
Eventually weight = air resistance
There is no resultant force and no acceleration
The forces are balanced and terminal velocity has been reached
Forces around a car
, Electricity:
Structure of a metal: regular arrangement of positive ions surrounded by
a sea of delocalised electrons
As temperature increases the positive metals ions vibrate more impeding
the flow of electrons meaning there is greater resistance within the wire of
a metal.
Resistance = voltage/current
It is difficult to measure the resistance of a component. Instead we add an
ammeter in series and a voltmeter in parallel to the component and take
these readings and use them in the equation resistance= voltage/current.
(N.B you’ll also need a variable resistor to enable you to take a range of
current and voltage readings)
Converting units:
mA → A (divide by 1000)
Random tips:
Independent variable: what you are changing
Dependent variable: what you are PHYSICALLY measuring e.g.
length, weight
Use a graph line to determine the value of n=sini/sinr because it
allows you to use all the data rather than just two points and you
can discount anomalies more easily
On graphs look for lines being directly proportional - the points
should go through the origin
With experimental design, always state ‘repeat and
calculate an average’
Megajoules to joules x 1000,000
Past exam question: investigating how temperature affects how
high a ball bounces
Independent variable: temperature change in a water bath
container
Dependent variable: height measured in m by a measuring rule that
the ball bounces
Control variables (+3): mass of the ball the same, same floor and
same force that the ball is dropped at and height ball is dropped
from
Repeats: repeat the whole experiment five times and find an
average excluding any anomalies
High-quality data: rule with small increments, use a camera and
view is slow motion
Forces:
How to investigate Hooke’s Law:
1. Hang a spring off a clamp stand
2. Measure the original length
3. Add a weight and measure the new length of spring
4. Repeat for a range of weights
5. Repeat and calculate an average
6. Plot a graph of length vs weight
7. Graph should be a straight line and pass through the origin
,At point A the limit of proportionality has been reached. And the spring
has been irreversibly damaged.
Terminal velocity:
Parachutist jumps out of the airplane
Weight acts downwards
Air resistance acts upwards
Object accelerates downwards
Eventually weight = air resistance
There is no resultant force and no acceleration
The forces are balanced and terminal velocity has been reached
Forces around a car
, Electricity:
Structure of a metal: regular arrangement of positive ions surrounded by
a sea of delocalised electrons
As temperature increases the positive metals ions vibrate more impeding
the flow of electrons meaning there is greater resistance within the wire of
a metal.
Resistance = voltage/current
It is difficult to measure the resistance of a component. Instead we add an
ammeter in series and a voltmeter in parallel to the component and take
these readings and use them in the equation resistance= voltage/current.
(N.B you’ll also need a variable resistor to enable you to take a range of
current and voltage readings)
