Key Points Paper 1 2020 Flashcards
(21 cards)
What are the four fundamental interactions and how do you spot them
STRONGEST
Strong - interactions between hadrons
Holds nucleus together
Em - interactions of charged particles
Attractive or repulsive
Weak - beta decay/electron capture
Lepton-Hadron interaction
Gravity - Between objects with mass
WEAKEST
What groups make up hadrons
Baryons + Mesons
(3q). (qAq)
Which force do leptons not interact via
Strong Nuclear
How does stopping potential relate to maximum kinetic energy
KE(max) = eVs
KE(max) - maximum kinetic energy
e - electron charge
Vs - stopping potential
What is stopping potential, Vs, defined as.
The potential difference required to stop photoelectron emission from occurring
How is the work function defined as
The minimum energy required to release a photo electron from the surface of a metal
What is the principle of superposition
When two or more waves overlap at a point, the displacement at that point is equal to the sun of the displacements of the individual waves.
What happens at a point of maximum on a screen during double slit.
The waves superpose at maximum points
What is the definition of path difference
The difference in distance travelled by two waves from their sources to the point where they meet
How do you work out the average speed from a speed time graph?
Work out the total displacement (Area under the graph) and then divide the total displacement by the total time taken.
How would your rearrange the resistivity equation to find resistance
P (rho) x L /A
State one advantage and one difficulty of using superconductors over long distances.
Advantage: >Has no resistance
>Reduce heat/energy transfer
Difficulty: >Must be kept above Critical Temperature
>Difficult to maintain low temperature over long distance
An electron collides with an isolated atom and raises an atomic electron to a higher energy level. What happens
The colliding electron transfers energy to the atomic electron.
How to find the wavelength from a drawing
Distance covered by a full cycle of the wave, usually measured from peak to peak, or trough to trough
[Small water drops leave a tap with zero velocity at intervals of 0.20 s.
They then fall freely 0.80 m to reach a horizontal surface.
How far has a drop fallen when the previous drop hits the surface?]
How would you work this out?
- Use a suvat to find the time taken to fall to the surface
- Find the difference in time by taking away the total time to fall by the interval.
- Use another suvat to find the distance travelled in the given time.
ANSWER= 0.2m
When using time in an efficiency equation which side of the fraction does it go on.
Time is an input power (Denominator)
When a mass on a spring is mentioned which equation should you use in order to find the frequency?
f=1/2pi x (K/M)^1/2
f-frequency
k-Spring constant (Stiffness)
m-Mass
What is the definition of spring constant.
The force per unit extension
(The spring constant is a measure of how stiff the spring is)
How can the mass be used ina young modulus equation?
Mass can be converted into weight (F=mg)
This force would go into the Young modulus equation.
What happens with resistance when temperature is changed in a thermistor.
If the Temperature decreases, Resistance increases
If the Temperature increases, Resistance decreases
In the equation to work out the time period of a Mass-Spring system, What is the timet period proportional to?
The time period is proportional to the root of the original Mass.
