Memorize or how to remember PHYSICS kinematics equation

[orangeblue]

I've seen the kinematics equation so many times, yet can't seem to find a quick easy way to recall them. It was the first passage/question on the MCAT I took and i flipped out at not knowing it on top of my fingers.
(With the SN2ed and BR resources, I am going to make sure the speed/etc issue doesn't happen again 🙂D )

How to remember the 4 kinematics equations quickly ? I know that a pair of them can be derived easily from the other..but still.


Please let me know how you memorized it!

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[DocE305]

You are going to use those equations so much you will be spitting them out by test time. Dont stress it.

 

[mspeedwagon]

Honestly, you'll have these down pretty quick. I can't forget them, I've done so many problems.

But, if you are still having problem closer to test day... memorize them shortly before you enter the test center and write them down as soon as you begin the tutorial.

 

[kmp0410]

Honestly, you'll have these down pretty quick. I can't forget them, I've done so many problems.

But, if you are still having problem closer to test day... memorize them shortly before you enter the test center and write them down as soon as you begin the tutorial.

This

I'm a believing in memorizing some things and writing them down at this stage.

Sometimes when its all in your head it can be easy to mix things up while reading a passage. But when you have them all there its kinda like having open notes.

 

[gettheleadout]

I agree with the other users that repeated exposure will burn them into your mind.

BUT, that said, if you want a way to make sure you have them right (who knows, you might second guess yourself)...

Each equation can be broken up into its terms and what they represent. Further, each equation can be grouped with another; there are two equations for displacement, and two for final velocity. For example:

Displacement A: dx = (v_0)t + (1/2)at^2

The first time is the distance traveled as a result of your initial movement, AKA how far you'd go if you kept constant velocity. The second term is the additional distance you travel beyond that as a result of changing your speed (or the distance less than that if you're slowing down). Naturally both of these things would need to be taken into account to determine how far you are displaced as a result of your movement.

Displacement B: dx = (1/2)(v_0 + v_f)t AKA dx = (v_avg)t

The only term to take into account here is your average velocity (calculated as a simple arithmetic average if you only have initial and final velocity) times your time. Naturally, displacement is rate of movement times the duration of movement, since (m/s)*s = m.

Velocity A: v_f = v_0 + at

The first term is your initial velocity, and the second is its change. Again, these are naturally the two components you would need to mentally reason out your final velocity.

This gets more difficult with the last one:

Velocity B: (v_f)^2 = (v_0)^2 + 2adx

I'll admit I don't really have a mnemonic explanation for that one haha, you might want to just memorize it. 😛

 

[Mehd School]

I just use the VAT, VAX, TAX, DVT trick.

As you're reading the question stem, if it gives you or asks for V, A, or T, then use VAT.
If, in the question stem, you are given, or it asks for V, A, or X, then use VAX.


And so on. It never fails me, and it's quick.

 

[Like]

Use the tutorial time to write down any equations on the scratch paper.
Saves time and you won't have to scramble trying to remember them during the section. 😛

 

[orangeblue]

I agree with the other users that repeated exposure will burn them into your mind.

BUT, that said, if you want a way to make sure you have them right (who knows, you might second guess yourself)...

Each equation can be broken up into its terms and what they represent. Further, each equation can be grouped with another; there are two equations for displacement, and two for final velocity. For example:

Displacement A: dx = (v_0)t + (1/2)at^2

The first time is the distance traveled as a result of your initial movement, AKA how far you'd go if you kept constant velocity. The second term is the additional distance you travel beyond that as a result of changing your speed (or the distance less than that if you're slowing down). Naturally both of these things would need to be taken into account to determine how far you are displaced as a result of your movement.

Displacement B: dx = (1/2)(v_0 + v_f)t AKA dx = (v_avg)t

The only term to take into account here is your average velocity (calculated as a simple arithmetic average if you only have initial and final velocity) times your time. Naturally, displacement is rate of movement times the duration of movement, since (m/s)*s = m.

Velocity A: v_f = v_0 + at

The first term is your initial velocity, and the second is its change. Again, these are naturally the two components you would need to mentally reason out your final velocity.

This gets more difficult with the last one:

Velocity B: (v_f)^2 = (v_0)^2 + 2adx

I'll admit I don't really have a mnemonic explanation for that one haha, you might want to just memorize it. 😛

love this! wow, AN epiphany!! i get it now...deep insights.. thanks so much!! sending you lots of positive wishes and much more!

 

[orangeblue]

one way to remember the 4th equation is:

velocity final will be = velocity initial component+ acceleration component

it's squared due to units:

if the right side of the equation is in velocity, the left side has to be in units of velocity too ( L/T)

Acceleration is L / T^2 and since this equation doesn't use t (time), you have to multiply the acceleration x distance to get it to L^2 / T ^2 , which is ofcourse velocity^2

 

[Amygdalarian]

I just use the VAT, VAX, TAX, DVT trick.

As you're reading the question stem, if it gives you or asks for V, A, or T, then use VAT.
If, in the question stem, you are given, or it asks for V, A, or X, then use VAX.


And so on. It never fails me, and it's quick.

This is awesome. Thanks!

 

[clothcut]

familiarity will make it effortless to remember test-day. however, i love how TBR derives these equations.... they make MUCH more sense intuitively thanks to that

 

[mehc012]

Personally, I just made a few flashcards with

GIVEN: couple of variables
FIND: variable

and the answer to the card is the equation to use. That way whenever I'm doing questions, I can just ask myself "what am I given? What do I want?" (which you should always do anyway) and the equation just pops into my head!

I also took the time to derive all of the convoluted equations from the easily explainable ones...aka it's clear to me why
vf = v0 + at
and it is also clear why
xf = x0 + v_avgt

From those, you can derive the rest, and once you make your own brain crunch all of the steps once or twice, they'll all be stuck, because you'll know WHY they work, not just that they do!

 

[orangeblue]

GOOD ideas, mehc!! Thanks a lot!!

 

[mcgst9]

I agree with the other users that repeated exposure will burn them into your mind.

BUT, that said, if you want a way to make sure you have them right (who knows, you might second guess yourself)...

Each equation can be broken up into its terms and what they represent. Further, each equation can be grouped with another; there are two equations for displacement, and two for final velocity. For example:

Displacement A: dx = (v_0)t + (1/2)at^2

The first time is the distance traveled as a result of your initial movement, AKA how far you'd go if you kept constant velocity. The second term is the additional distance you travel beyond that as a result of changing your speed (or the distance less than that if you're slowing down). Naturally both of these things would need to be taken into account to determine how far you are displaced as a result of your movement.

Displacement B: dx = (1/2)(v_0 + v_f)t AKA dx = (v_avg)t

The only term to take into account here is your average velocity (calculated as a simple arithmetic average if you only have initial and final velocity) times your time. Naturally, displacement is rate of movement times the duration of movement, since (m/s)*s = m.

Velocity A: v_f = v_0 + at

The first term is your initial velocity, and the second is its change. Again, these are naturally the two components you would need to mentally reason out your final velocity.

This gets more difficult with the last one:

Velocity B: (v_f)^2 = (v_0)^2 + 2adx

I'll admit I don't really have a mnemonic explanation for that one haha, you might want to just memorize it. 😛

I remember the last one as d = (Vf^2 - Vi^2)/2a

I remember seeing a problem on one of the question of the day sites, and they listed the equation like that, and it just stuck ever since.

 

[mehc012]

GOOD ideas, mehc!! Thanks a lot!!

Thanks! I like the flashcard one because it's pretty much the only equation-based flashcard I could come up with that tested how I approached a problem and chose my tools, rather than memorizing a single specific example or just memorizing the equations out of context! Hope it helps!

 

[lcollier7]

Are you allowed to start writing on scratch paper when the tutorial begins or do you have To wait until you begin PS section?

 

[mcgst9]

Are you allowed to start writing on scratch paper when the tutorial begins or do you have To wait until you begin PS section?

I'd like to know the answer to this as well. I planned to write down as many equations as I could remember so I'd be able to see them on paper should I need them.

 

[lcollier7]

Yeah if you can that's great- I tried doing a formula sheet after time had started on PS section and I ended up running out of time (due to the time lost writing down formulas) so I kinda stopped trying to memorize my formula sheet ad just memorize the formulas individually as needed- I think that you are much more prone to error this way though

 

[QrtrLifeCrisis]

Are you allowed to start writing on scratch paper when the tutorial begins or do you have To wait until you begin PS section?

Apparently, that depends on which test center you attend. I took the MCAT twice, in two different locations. I was specifically told not to start writing on the scratch paper until the PS clock began during my first go, but was not given that restriction during my second go.

I called AAMC after my first exam and the representative said that there was no policy against writing on scratch paper during the tutorial section so it must have been either the crazy woman checking me in or the policy of that specific testing location. Either way, I would either call your testing center to find out or just ignore them and go ahead and write on the scratch paper anyway during the tutorials. The worst they could do is come by and tell you to stop, but seeing as how it isn't AAMC policy, I don't believe they could do much more.

All that being said, I hardly used my formula sheet. I'm still impressed by how much I was able to vomit before the section began, but the exam isn't about plugging and chugging -- it's about taking a concept and twisting it up until it's hardly recognizable anymore.

 

[MCATMountain]

Make sense of them. For example, Vfinal = Vinitial + at. The final velocity necessarily has to be the initial velocity plus the change in velocity. Velocity changes with acceleration. So the acceleration over a time frame shows the change in velocity. If you make sense of them like this, it'll be harder to forget.

 

[Jesus1]

Use them extensively with EK 1001 questions.After a while you won't forget them.They'll stay with you for a long time.