Physics Homework :3 ~Help!

And in what planet is g=4.46m/s^2?

 

Ur anus

 

I like how you yourself said it's a free fall and still used the speed=distance/time formula.
It is known that in free fall, v=gt like you perfectly mentioned and h=1/2gt^2 so even by replacing h in the formula you claim to be true, it goes v=h/t => v=(1/2gt^2)/t => v=1/2gt which doesn't exist anywhere. Or if you even use the two formulas you mentioned, v=h/t and v=gt, that means that h/t=gt which means h=gt^2 which is also false, look at the yellow picture below. That should tell you that v=h/t and v=gt do not apply for the same circumstances.

Quoted below:

and since there's obviously an acceleration that we're trying to find, in our case it's G, it's obvious that V will not stay the same therefore the v=h/t formula does not apply.

If h=2 and t=0,67 then use the given formula for height traveled, h=1/2gt^2 => 2=1/2g0.67^2 => 2=1/2g0.4489 in which case g=approx 8.9m/s^2, which still wouldn't make sense on earth, but it sounds more logical than the 4.46 as posted above.

And if you're wondering how the h=1/2gt^2 was formed, take a look at this little picture right here:



As explained, V=Vo+at which in free fall turns into V=gt since there's no speed at the beginning (when you leave an object from a certain height with your hand the kinetic energy on the point where you drop it from is 0 and the gravitational energy is max (but gravitational potential energy is another thing so nevermind it), and a turns to g because we call it gravitation of earth and it's not just any acceleration, therefore V=Vo+at becomes V=gt). Also fun fact since I mentioned gravitational energy, you will later find that on the very bottom part where the object touches the ground, the kitetic energy will be maxed and the gravitational potential energy will be zero, opposite of the top part. And that happens because all the gravitational potential energy the object had at the top point, turns into kinetic energy at the bottom.

Sorry no.

 

Wait, so teh answer is wrong?

Btw Uranus was a joke, I used to say that when I was small.

 

@Dimitra @Anonymous

 

You're butthurt Dimitra?
I'm sorry but all i could think of right now was: "Culture is like jam - the less of it you have, the more you spread it"

Thanks for correcting it; it's just the manner of doing it that i don't like

 

V=h/t only works when V stays the same as stated in the quote I posted, and since we have an acceleration, in which case it is the earth's acceleration (gravity) and it is known that acceleration changes V, then yes, the first answer is incorrect. Look at my reply for a different opinion, but at the same time I don't know what kind of teacher would give their students a problem where the answer for g is 8.9m/s^2 since on earth it is close to 10 and everybody knows that.

In my 4 years doing similar physics problems while still in school, I only once stumbled upon a problem that asked me to find G, and it ended up being a straight 10 (which is still not correct, but it makes more sense than what you are given since you will see that in future problems you will be given g=10m/s^2 approximately).

I haven't done anything like that in over 3 years so excuse me for butting in if the answer is incorrect, but I'm confident that the answer where v=h/t is used is definitely wrong and you don't wanna use it cause it defies the purpose of a free fall.

No, not at all, I'm just correcting the mistakes of a supposed 24 year old engineer as a 19 year old finance student.

 

#Rekt

 

@DivineGodZ Try not to Double post. If you have to post two times before someone else replies, just click "Edit" under your first post.

 

And then you found the "G" called Moe, he was so damn fly.

God Bless

I'll cut you if you say: G=Gay

 

I dont get the last part:

2=1/2g0.4489 in which case g=approx 8.9m/s^2

 

@Dimitra @Kretia

And I'm going to correct the mistakes of a 24 year old engineer and a 19 year old finance student as a 26 year old Monster Slayer.

The answer is Chuck Norris. Put that in and you get full credit. Make that the answer for EVERY question and you get straight A's.

What is gravity? Chuck Norris

What is the best way to slay a horned spiketail dragon? Chuck Norris

What is the difference between flora and fauna? Chuck Norris

An evil necromancer is summoning an army of undead to take over the world. Do you kill him first in the hopes that the undead will disintegrate or do you destroy the undead first in case the necromancer is in charge of any limits of the undead and without him the undead will have free reign to plunder, kill, rape churches, and burn women with no one to control them? Chuck Norris

 

I wrote it down replacing each given number on a piece of paper for you x.x

That's pretty much the whole problem, my wall of text was pretty much an explanation on why it is like that.

 

This.

 

It goes to 2 = g*0.22445 in which case you divide 2 by 0.22445 to solve for g and you get 8.9106blabla

 

Sadly you are wrong dimitra.

You need to focus on the fact that G (Gravitation) is our unknwon facton, so our X.
We are not taking the earth as model, there is nothing written about it.

We need to find the value of G which makes our Ball fall from a height of 2 meters in 0,67 seconds.

Gravitation is nothing but accelleration, thus A=V/T -> G=V/T.
However, we are still missing V, which can easily be obtained thanks to the general formula V=S/T. Our S (Space) is 2 meters, our T (Time) is 0,67 seconds.

V= 2 Meters / 0,67 seconds -> 2,98 m/s

Now we can proceed with calculating G.

G=2,98 m/s / 0,67 s = 4,44 m/s^2.

Your formula was used to calculate G on earth, not G in an unknown environment. Sorry but Kretia's post is correct while yours is not.

 

I keep getting other answers..
Sorry but i cant get to 8.9?

 

And rekt.


Though you can still put Chuck Norris as the answer and get full credit.

 

Quoting again:

The V=S/T "general formula" like you said (S=VT as posted in the quoted picture), can ONLY be used when V is one stable number. For example when V=2m/s at any given moment. Acceleration means that at any given moment the velocity changes, so it's not the same number all the time. That's why we talk about speed at the highest point and speed at the lowest point, because velocity changes as the object falls. Therefore V=S/T does NOT apply in a free fall.

I'm pretty much explaining the same thing again.
TL;DR, V=S/T does NOT apply in the cases where a (acceleration) is active. If you want the proof why it doesn't apply, then you can go replace the V=S/T formula in the formulas that apply for free fall like I did above (v=gt and h=1/2gt^2). It comes up with false formulas that don't exist.
It's the way it is. Can't change it.

The only thing I will agree with you on is that the object is not said to be falling on earth, which answers my questions about why g=8.6m/s^2 and not 9.8m/s^2. Maybe the object is being left to fall in Uranus like divine said for all I know. But it's still 8.6 and not 4.4.

 

Gais, seriously gais. Are we gonna spend all this time and effort on some punk kid's math problem?

Seriously gais?!

Gais!?

Come on gais.

Let's do something else.

Like have an orgy.