Answers

Question 1

A potential dicider circuit , can one resistance be proprtional?

Answer 1

No meber completely proportional becsuse if value of other resitsnce

Question 2

Explain why resitsnceis constant, say

Answer 2

The gradient is fairly linear to thst point and show a clacualtion

Question 3

Gotta see the parallel circuit, don’t assume no resistance

Question 4

How to get greatest swing on potentiometer

Answer 4

If your resistor so low, no matter what happens to variable resistor (goes low) goes high, then it doesn’t matter itwon’t make too much of a difference lol

If it is so high, then again it will just take majority volt anyways so not much difference

Therefiremudt be as close to middle of the range thst variabel csn go to, do that the effect actually seen

So if your range 100-1000 and reguakrly moves through this, you want it to be at 550 ideally

Question 5

How to make a potentiometer

What does this let you do

And why do you use a bother permanent rejector if it’s something like a light bulb

Answer 5

Basically arrow is half way through permanent resistor, connect you comoientnand ammeter in series and then voltmeter in parallel

This lets you measure the full range of volstage fromm0 to abwäge

Nothing is there to limit the current of the bulb, thus use a resistor that lowers current to protect it

Question 6

Why might yiu need to add a resistor!

Answer 6

To protect component reducing resistance, check the specs they giv you

Question 7

Okay what is not equal to emf when there is internal resistance

How is internal resistance alwyas plot, don’t complicate things

Answer 7

Itsalways jus split like potential divider to resitsmces in the whole circuit

The electrical energy produced is the terminal pd

The chemical energy thst is converted is = to the emf, but then this is lost aswell

So electrical energy produced is not emf

Question 8

When talking about something being less bright what can you talk about

Answer 8

Talk about what happened ti voltsge and curren t(because resistsnce increased) and thus power

So basically don’t just say voltsge decreased if you can

Question 9

Explain why when a s write is closed voltsge is lost

Answer 9

This is because
- batterynhas internal resistance, so this causes lost volts as the charge carriers lose energy as heat when being cinverted . This is because the emf is now split between the internal resistance and the external resistances tin

Thus voltmeter drops

Question 10

How to do gravity into frictional lost

Answer 10

So work out how much FIRCE yiu should’ve had at the bottom by converting work done into gpe
Then do f= ma which tells you how much you acc have at the bottom

Subtract

This is frictional work

Question 11

I guess when doing height vs,cusktions try use the best variables possible so not over complicate

Answer 11

So like take values thst are actually relevant to the path etc

Question 12

HOW TI FIND ANGLE BETWEEN KICK SND PROJECTILE MOTION

Answer 12

NEVER USE DISTANCE! USE YOU INITSL VELOCITY HORXINALT AND VERTICAL AND DO TAMN

Question 13

Safe answer when do projetileshave highest kinetic energy

Answer 13

If not air resistance,e then either at the start or at the end because thatsgreatest velocity

But because if resistance, start is always corrects reistsnce can cause less velocity at the end thus

Question 14

Energy change from GPE TO KE

Answer 14

GOE ti KE which chnaged to heat energy

Even when applied by air resistance this creates heat

Question 15

MAKE SURE WHEN DOING MOMENTUM THINGD OR ANYTHING TI CHEKC GHR DIFECTIONS , CAN GET WHOLE ANSWER WRONG!

Question 16

Why does material of object something is landing on importsnt to calculate Montur and forces etc

Answer 16

Because a softer material means time of impact is longer so force of impact is LESS

If harder then time is less, force is GREATER (and so more likely to break)

However apparently a softer Landing decreases change of momentum so it reduces height? Idek waffle

Question 17

Remmeber why does a car force decreases

Answer 17

Beachside is speed increases drag increases by square, meanin resultant force decreasing and decreasing

Once the thrust = resisitve firces (air and friction) then it will move at terminak velocity

Question 18

Remember for anything Archimedes type principle don’t find shortcuts just state the principle and work from there

Answer 18

Also remmeber uothrust isn’t mg its d h g a

Question 19

Why is densities the main factor to see if something flowt or sink

Answer 19

Because volume is constant in bith, so that cancels, it ends up going down to doenskth over density

Question 20

Why model wood as diver

Answer 20

Similar density sd human

Which is required as humans dive than float agsin

Question 21

Describe and explain how resuktentnfirfe on wooden cylinder wires from moment it is fully submerged

Answer 21

Basically above the ground it has resultant five G, which decreases as it gains speed and thus drag. So it is decreasing acceleration

Upon entering the water the reduktent firfe decreases and once fully submerged,Erreger the resuktsnt firfe is upwards made from uothrust which is always more than the weight and drag.

However as it begins to decelerate and lose speed it loses drag too, so resultant FIRCE upwards decreased until at loses tpoijtnthere is no drag , just resultant force upwards caused by the drag

This results in the bidy ti begin to accelerate upwards, gaining resultant force as drag acts once again as it gains speed and gains drag too, until it eventually hits the surface where it floats and uothrust is now = to its weight snd now constant velocity .

Question 22

Bruv check equilibrium questions that atleast net force is 0 first, makes ir a lot lot easier!

Question 23

Don’t be dumb , remember for equilibrium , it has to have net force 0 in every plane, and also net moment 0 about any point . Thus if you stuck with firces, or stuck with moments LOOK AT THE OTHER ONE FOR HELPPP

Question 24

Make sure to use all formulae first

Question 25

Why when a car lowers on fuel does it become faster overall

Answer 25

Decrease in fuel means increase in acceleration, so maximum acceleration and deceleration increase

The MAX SPEED IS NIT INCREASED BECAUSE MAX THRUST IS STILL THERE, limited by drag

Question 26

What is centre of mass

Answer 26

Point at which all the mass is said to be cicnentrated at

Point at which if a FIRCE is applied through the centre of mass, no rotational movement is seen

Question 27

FOR SIGNRICANR FAIGURE WHAT TO DO

Answer 27

Make sure you do lowest in the answer and if it is 0 then make sure you WRITE THIS LOSE A MARK

Question 28

Moments remember why do we often not twke the horizontal component of tension

Answer 28

Be Ayse it runs in the samemplame as the pivot

Question 29

Remember for PREFIX CONVERDIONS, JUST ASSUMED GIGA IS 106 WHEN IRS TO THE POEER OF 9 FIX UP

Question 30

Make sure when explaining explain all thoughts, give directions and moment key terminology for Marks

Question 31

In seiosmeter question why does the one go up and not down straight away?

Answer 31

Downarads accekerwtiin if the ball is mucus keds than the frame so relatively frame goes down whilst ball stays where it is and then a mark goes up, however then it goes downnagterndue ti spring and it moving too

Question 32

Don’t be fooled! If something is IDENTICAL MATERIAL , but less area and length (which you know to not contribute ) wha this young modulus

Answer 32

Still the same! Same material = same young modulus

Question 33

BRUH how to work out energy stired elasticallg in young modulus equation

Answer 33

Basically itnis the same as 1/2 f x X

So make equation fir force and sub in 😭 acc sad

Question 34

BRUH ir said OJE SLRING , don’t get caught out by two springs when it already became one be careful

Question 35

Confirmed = thermal energy in loading unloading is just ?

Answer 35

Area in between

Question 36

Bruv you were correct for spring constant strain energy forumsl is still 1/2 k x 2 or 2/2 f x just need to sub in k is stiffness and if not then sub in for,usk for f that’s calm

Question 37

Springs or cables, if in series the force across both is the SAME, don’t confuse and add force from cable

Answer 37

!!

Question 38

Remember low resitivty means high current, so it made sense for it to go around the ring and middle for mechanical strength !

Question 39

Make sure proprtionsl laws etc are still good!

Question 40

Abkut waves and snell

Answer 40

Remember equation fir n , is ratio of speed of something in thr speed of light

When something gets refracted snd becomes faster, wavelentgh becomes lomger, and wavelentgh becomes shorter if it gets slower

The lower the reflarsfive jndex if entering the greater the angle

And also if they refract by same amount probably because they have the same refractive indes

Question 41

Coherence primarily conserves what! Frequency or phase difference

Answer 41

It conserved PHASE DIFFERENCE , and as a result sre the same feewuency !