Final Exam Mistakes

Question 1

I think change of monetuj in one object = to change of momentum in another

Answer 1

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

Question 2

So Yh make sure change of monetuj decide on the sign fitet

Answer 2

Here as it goes oppsite direction itsgonna habe tk be negative

Question 3

Find out change in velocity?

Answer 3

Use the monetuje snd Impulse and rearrange and yiu get expression for change!

Coulda been wasier because it was at rest too!

Question 4

If FORCE ON FT GRAPH CINSTSNT WHAT DOES THIS MEAN FIR VELOCITY

Answer 4

As resuktsnt force is constant, so is accerlwtion , constant accerlwtion means CONSTSNT increase in velocity .

Question 5

OKAY SO HOW TO FIND OUT ENERGY FIVEN TO GROUND WITH BEFORE AFTER

Answer 5

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

Question 6

Firce recieved on an object = to impulse per secon how?

Answer 6

Bevsuse impulse per second = force! RIGHT ALL UNITS OUT AND SEE OPTIONS

Question 7

Some of these graohs have to follow symmetrical patterns too so use thst

Question 8

Why at the same height , with no resistance and you fall down, is finsk velocity the same?

Answer 8

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!

Question 9

Basic new equation for final Feld out using impulse if initsl 0

Answer 9

Ft= mv

Question 10

How to do that really weird q , typically with big unitd how to go about

Answer 10

Yh work with units but remember your original equation which is still mv

And since it was per second csn get rid

Question 11

IN MOMENTUM EMISSION AUESTIONS WHAT TO REMEMBER ABOUT NEW MASS?

Answer 11

NEE MASS IS MASS - OLD MASS

Question 12

Oh so how do you find best estimates of calculations using uncertainties ? And what rule

Answer 12

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 !

Question 13

For thst best value for ucnersirny snd accuracy

Answer 13

The range has to atleast meet

And also like just more closer I guese

Question 14

Uncertiwnties for adding and subtracting are different, how to solve?

Answer 14

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

Question 15

Again how to work out percentage uncertainty adding subtract and absolutes

Answer 15

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

Question 16

Be wary of the displacement time graphs , where the wavelength is thr time period = the time taken for one wave to pasd

Question 17

How to describe how points nodes and antinides occur on stationary waves

Answer 17

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

Question 18

Describing motion of wave

Answer 18

Again first
1) trsnverdeor what = describe thst
2) if times use this
3) goes max positbe displacement equilibrium negative

Question 19

Definition for progressive wave

Answer 19

Transfers energy without matter

From a point to a source

Question 20

Coherent full

Answer 20

First phase difference
Then frequency

Question 21

Explain fully how wvakentgh s go from same to quiet and loud because of PLD, why

Answer 21

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

Question 22

How does the knot specifically become stationary when superpose by standing, what you have to say?

Answer 22

It has to be at a node! So it don’t move because there are puts that move so yh

And also

Question 23

Stationary wave conditond

Answer 23

Same medium p
Gotta be SAME FREQUENCY coherent

Oppsite direcjrons

Question 24

WHEN DOING STATIONARY harmonics, when the fundamentals frewuency changes the Knetgummis of string is the same

Question 25

How to show energy dissaptedin a circuit is equal to energy out

Answer 25

So power in , and then show power out at all resistors

Question 26

FIR ELECTRICITY , want to get from point A TO B , how do you go

Answer 26

Find all routes to get there, and REMAKE A CIRCUIT AND NOW FIND ANSWE

Question 27

If two cells are reversed, what to do

Answer 27

Cancel them out like vectors, draw arrows

Question 28

If you lose 1% power, what do you lose

Answer 28

Also 1% volts but currents are the same

Question 29

Circuits, can treat the v as itd Ken thing if internal resistsnce is like another resistor in the circuit !

Answer 29

And Yh thermal energy lost is just = to power
And if it says cell then it meansss cell!

Question 30

If something falling down ramp how to find final velocity?

Answer 30

Suvst or average velocity

Question 31

Remember if it probably not constant,t it’s a constant deceleration , so use suvst to work out time