Final Exam Mistakes Flashcards
I think change of monetuj in one object = to change of momentum in another
So if one thing changed by 20, so itsother!
And if change if Monstrum is not specific Ed, not to write the direction first, here this is impulse oppsite then change is negative
So Yh make sure change of monetuj decide on the sign fitet
Here as it goes oppsite direction itsgonna habe tk be negative
Find out change in velocity?
Use the monetuje snd Impulse and rearrange and yiu get expression for change!
Coulda been wasier because it was at rest too!
If FORCE ON FT GRAPH CINSTSNT WHAT DOES THIS MEAN FIR VELOCITY
As resuktsnt force is constant, so is accerlwtion , constant accerlwtion means CONSTSNT increase in velocity .
OKAY SO HOW TO FIND OUT ENERGY FIVEN TO GROUND WITH BEFORE AFTER
Energy hitting ground find out, energy after leaving the ground, difference is what’s trasnferedto the ground
And how to find out force?
Again change if monetuj /time, but have to pick vectors and state the, properly ! As can get wrong
Firce recieved on an object = to impulse per secon how?
Bevsuse impulse per second = force! RIGHT ALL UNITS OUT AND SEE OPTIONS
Some of these graohs have to follow symmetrical patterns too so use thst
Why at the same height , with no resistance and you fall down, is finsk velocity the same?
Because mgh is Converter to ke, such thst masses cancel, and no matter what the v jus depends on height, so if h the same so is v!
Basic new equation for final Feld out using impulse if initsl 0
Ft= mv
How to do that really weird q , typically with big unitd how to go about
Yh work with units but remember your original equation which is still mv
And since it was per second csn get rid
IN MOMENTUM EMISSION AUESTIONS WHAT TO REMEMBER ABOUT NEW MASS?
NEE MASS IS MASS - OLD MASS
Oh so how do you find best estimates of calculations using uncertainties ? And what rule
Generally thst uncertainties are given to 1SF
Also that the absolute uncertainty of the total area is the ADDITION OF THE PERCENTAGE UNCERTAINTIES SEPARATELY, then MULTIPLIED BY THE TOTAL AREA FOR THE ABSOLUTE !
For thst best value for ucnersirny snd accuracy
The range has to atleast meet
And also like just more closer I guese
Uncertiwnties for adding and subtracting are different, how to solve?
Find upper bound
And lower bound
And normal
And the difference between these must be CONSTSNT, so this id the absolute
Yet however remember for multiply and dividing you can use uncertainty methor
Again how to work out percentage uncertainty adding subtract and absolutes
Adding = upper bound and lower bound against actual will give you absolute, uncertainty is absolute over actual
Multiplying dividing can jus do absolute / answer
To find new absilute find percentage uncertainties add 5em multiply by the new vslue
Be wary of the displacement time graphs , where the wavelength is thr time period = the time taken for one wave to pasd
How to describe how points nodes and antinides occur on stationary waves
Yh first two progressive coherent hit reflect 180, and thus superpose to make stationary waves
Then say points which are per neatly out of ohase interfer to make destructive interference etc
So PERMANENTLY in and OUT OF PHASE
Describing motion of wave
Again first
1) trsnverdeor what = describe thst
2) if times use this
3) goes max positbe displacement equilibrium negative
Definition for progressive wave
Transfers energy without matter
From a point to a source
Coherent full
First phase difference
Then frequency
Explain fully how wvakentgh s go from same to quiet and loud because of PLD, why
This because it is out of phase and most when it hits 1/5 wavlentgh apart, then begins to become slightly in phase until max at a wvakentgh apart
How does the knot specifically become stationary when superpose by standing, what you have to say?
It has to be at a node! So it don’t move because there are puts that move so yh
And also
Stationary wave conditond
Same medium p
Gotta be SAME FREQUENCY coherent
Oppsite direcjrons
WHEN DOING STATIONARY harmonics, when the fundamentals frewuency changes the Knetgummis of string is the same
How to show energy dissaptedin a circuit is equal to energy out
So power in , and then show power out at all resistors
FIR ELECTRICITY , want to get from point A TO B , how do you go
Find all routes to get there, and REMAKE A CIRCUIT AND NOW FIND ANSWE
If two cells are reversed, what to do
Cancel them out like vectors, draw arrows
If you lose 1% power, what do you lose
Also 1% volts but currents are the same
Circuits, can treat the v as itd Ken thing if internal resistsnce is like another resistor in the circuit !
And Yh thermal energy lost is just = to power
And if it says cell then it meansss cell!
If something falling down ramp how to find final velocity?
Suvst or average velocity
Remember if it probably not constant,t it’s a constant deceleration , so use suvst to work out time
