Simple physics question

[Vegitto]

I've got a car that weighs 1000 kg. How many energy would I need to accelerate this car from 0 m/s to 13 8/9th m/s?

Thanks in advance, I really suck at this.

EDIT: Or just a bump in the general direction would be OK. I don't want you guys to do my homework 😛.

 

[Whoozyerdaddy]

Originally posted by: Vegitto

Thanks in advance, I really suck at this.

Advice: Pick another major.

 

[neutralizer]

Originally posted by: Whoozyerdaddy

Originally posted by: Vegitto

Thanks in advance, I really suck at this.

Advice: Pick another major.

Could be just a required class.

 

[Vegitto]

Originally posted by: Whoozyerdaddy

Originally posted by: Vegitto

Thanks in advance, I really suck at this.

Advice: Pick another major.

Heh. Our teacher sucks. I'm in HS, though.

He doesn't even know this stuff. And he's supposed to teach it to us. "Err.. Well, the little booklet that came with this says the answer is xxx.. But I don't really understand how they got it.. Oh, wait! No, you're supposed to multiply those, not substract them from each other!"

 

[dighn]

KE = 1/2*mass*velocity^2

^you should learn from the book instead

 

[Vegitto]

Originally posted by: dighn
KE = 1/2*mass*velocity^2

I already got that.. 😛
So that's the answer.. Weird. But that answer is in Joules, or Nm. I need to substract Ffriction (100N), and I also need to know s in Wtot (Wtot = Fres x s x cos a)..

EDIT: I guess I should.. That's why I know more than my teacher 😛. I suspect him of being a drunk.. He always reeks.

 

[neutralizer]

Originally posted by: Vegitto

Originally posted by: dighn
KE = 1/2*mass*velocity^2

I already got that.. 😛
So that's the answer.. Weird. But that answer is in Joules, or Nm. I need to substract Ffriction (100N), and I also need to know s in Wtot (Wtot = Fres x s x cos a)..

WTF is Wtot and Fres?

 

[dighn]

Originally posted by: Vegitto

Originally posted by: dighn
KE = 1/2*mass*velocity^2

I already got that.. 😛
So that's the answer.. Weird. But that answer is in Joules, or Nm. I need to substract Ffriction (100N), and I also need to know s in Wtot (Wtot = Fres x s x cos a)..

kinetic energy is in joules.. which is equivalent to Nm

you didn't say anythinga bout friction. what elese did you leave out?!

 

[Vegitto]

Originally posted by: neutralizer

Originally posted by: Vegitto

Originally posted by: dighn
KE = 1/2*mass*velocity^2

I already got that.. 😛
So that's the answer.. Weird. But that answer is in Joules, or Nm. I need to substract Ffriction (100N), and I also need to know s in Wtot (Wtot = Fres x s x cos a)..

WTF is Wtot and Fres?

Wtot = I don't know if you guys use that.. Work total?
Fres = Fresulting (Fmotor-Ffriction)

 

[imported_Lucifer]

Your sig is annoying.

 

[neutralizer]

Originally posted by: Vegitto

Originally posted by: neutralizer

Originally posted by: Vegitto

Originally posted by: dighn
KE = 1/2*mass*velocity^2

I already got that.. 😛
So that's the answer.. Weird. But that answer is in Joules, or Nm. I need to substract Ffriction (100N), and I also need to know s in Wtot (Wtot = Fres x s x cos a)..

WTF is Wtot and Fres?

Wtot = I don't know if you guys use that.. Work total?
Fres = Fresulting (Fmotor-Ffriction)

What about s and a?

 

[Vegitto]

Originally posted by: dighn

Originally posted by: Vegitto

Originally posted by: dighn
KE = 1/2*mass*velocity^2

I already got that.. 😛
So that's the answer.. Weird. But that answer is in Joules, or Nm. I need to substract Ffriction (100N), and I also need to know s in Wtot (Wtot = Fres x s x cos a)..

kinetic energy is in joules.. which is equivalent to Nm

you didn't say anythinga bout friction. what elese did you leave out?!

Here's the whole question:

Car (1000kg) traveling at 13 8/9th m/s. Car stops just before it reaches a mountain(ish thingie) going up 10 degrees. (So, you're on the flat side, and you're about to go up.)
Whilst ascending, the car undergoes an average 100N in Ffriction. How far can the car go until it loses its speed?
Also calculate Fmotor.

 

[Whoozyerdaddy]

Originally posted by: Vegitto

Originally posted by: Whoozyerdaddy

Originally posted by: Vegitto

Thanks in advance, I really suck at this.

Advice: Pick another major.

Heh. Our teacher sucks. I'm in HS, though.

He doesn't even know this stuff. And he's supposed to teach it to us. "Err.. Well, the little booklet that came with this says the answer is xxx.. But I don't really understand how they got it.. Oh, wait! No, you're supposed to multiply those, not substract them from each other!"

Sorry to hear that.

 

[Vegitto]

Originally posted by: neutralizer

Originally posted by: Vegitto

Originally posted by: neutralizer

Originally posted by: Vegitto

Originally posted by: dighn
KE = 1/2*mass*velocity^2

I already got that.. 😛
So that's the answer.. Weird. But that answer is in Joules, or Nm. I need to substract Ffriction (100N), and I also need to know s in Wtot (Wtot = Fres x s x cos a)..

WTF is Wtot and Fres?

Wtot = I don't know if you guys use that.. Work total?
Fres = Fresulting (Fmotor-Ffriction)

What about s and a?

s is total distance traveled
a is the number of degrees between s and Fres.

 

[Vegitto]

Originally posted by: Lucifer
Your sig is annoying.

But I have so much to say! 🙁

 

[Vegitto]

Originally posted by: Whoozyerdaddy

Originally posted by: Vegitto

Originally posted by: Whoozyerdaddy

Originally posted by: Vegitto

Thanks in advance, I really suck at this.

Advice: Pick another major.

Heh. Our teacher sucks. I'm in HS, though.

He doesn't even know this stuff. And he's supposed to teach it to us. "Err.. Well, the little booklet that came with this says the answer is xxx.. But I don't really understand how they got it.. Oh, wait! No, you're supposed to multiply those, not substract them from each other!"

Sorry to hear that.

Heh. Yeah, me too 😛. Starting next chapter, fsck him. Book only. He tried to convince me that resistance was I/U instead of U/I.. Dumbass.

 

[imported_Lucifer]

LOL your physics teacher reminds me of my old HS physics teacher. Except he fell asleep at random sometimes. He would confuse himself and he would have to start over most the time.

 

[Vegitto]

Yes! He falls asleep a lot in class, and he picks his nose.

EDIT: The test is coming up real soon.. I used to do okay since my old physics teacher lived nearby, and he would usually teach me a bunch.. His wife passed away this summer and he's in a retirement home, now.. No visits allowed unless you're direct family 🙁. Poor guy.

 

[Vegitto]

I wish Dr Pizza was here.. He teaches physics, right?

EDIT: I feel like there's not enough information given in the assignment.. Am I correct?

 

[dighn]

you can solve it by going

lost kinetic energy (1/2mv^2) = energy dissipated through friction (f*d) + energy went into gravitation potential (mg*h)

 

[Vegitto]

Okay, and f would be friction (100N).
d would be? Duration?
g would be 1000kg x 9.81N
And h would be..?

Sorry, never heard of this formula before.

 

[Vegitto]

d = diameter? 😕

 

[dighn]

look up the sections about work and gravitional potential energy
work = F*d = force * distance
GPE can be approximiated by mgh = mass * gravity acceleration (9.8) * height

 

[Vegitto]

I don't know the distance (that's what the question is 😛).. And I also don't know the change in height. Sorry for being so hard on you 😛.

EDIT: You reckon height and distance are related? Man, this is hard..

 

[nycxandy]

Originally posted by: Lucifer
Your sig is annoying.

Not to sh!t in this thread or anything, but with a signature that big, it's hard to sift through all the replies.