Share something pointless about your life!

Printable View

Show 15 post(s) from this thread on one page

August 27, 2013
Orphic

Any of you ****ers good at Physics?

My teacher hasn't actually taught us **** or shown us any examples so I'm incredibly confused. I've managed to answer 11/15 questions on my assignment and have a 70.8% so far (which means I only have 2-3% wrong) but it's so slow and aggravating.
August 27, 2013
Link

Quote:

Originally Posted by Ptolemy

Any of you ****ers good at Physics?

My teacher hasn't actually taught us **** or shown us any examples so I'm incredibly confused. I've managed to answer 11/15 questions on my assignment and have a 70.8% so far (which means I only have 2-3% wrong) but it's so slow and aggravating.

REMEMBER d=rt, it is pronounced dirt.
We couldn't stop laughing when our teacher said that, she has a mullet and looks like
http://www.haro-online.com/stuff/joedirt.jpg
August 27, 2013
Orphic

A man throws a ball into the air. After 0.8 seconds it reaches a height of 38 feet. What was the initial velocity? How long did it take for the ball to reach 19 feet and what was the velocity at the time? Ignore air resistance.
August 28, 2013
Link

(D2-D1)/(T2-T1)=velocity(I think) and d=rt
T2=second time
T1=first time
D2=second distance
D1=first distance
And then your going to need d=rt to find out the velocity at 19 feet
+ initial velocity is 0

Spoiler: Show

I could be really wrong, physics was extremely boring with an extremely slow paced teacher for me

Spoiler: Show

velocity at 38 feet = 47.5 feet per second
then use use another equation I don't know how to write, a variation of the first one to get rid of second
47.5 feet per second / .4 seconds = 19 feet
so it took .4 seconds to reach that far
And now I can't rememer what to do to find out what the velocity is at that time, just uhhh divide the velocity i got at first by half and we'll call it good.
August 28, 2013
BlueAo

Quote:

Originally Posted by Link

(D2-D1)/(T2-T1)=velocity(I think) and d=rt
T2=second time
T1=first time
D2=second distance
D1=first distance
And then your going to need d=rt to find out the velocity at 19 feet
+ initial velocity is 0

Spoiler: Show

I could be really wrong, physics was extremely boring with an extremely slow paced teacher for me

Spoiler: Show

velocity at 38 feet = 47.5 feet per second
then use use another equation I don't know how to write, a variation of the first one to get rid of second
47.5 feet per second / .4 seconds = 19 feet
so it took .4 seconds to reach that far
And now I can't rememer what to do to find out what the velocity is at that time, just uhhh divide the velocity i got at first by half and we'll call it good.

You need gravity in order to solve this, the ball can travel infinitely if there is nothing to pull it back down, and speed diminishes exponentially with height, so you can not just half the maximum. ^^

I don't know to calc in feet so I'll call it a day. :|
August 28, 2013
Link

Quote:

Originally Posted by BlueAo

You need gravity in order to solve this, the ball can travel infinitely if there is nothing to pull it back down, and speed diminishes exponentially with height, so you can not just half the maximum. ^^

I don't know to calc in feet so I'll call it a day. :|

Gravity pulls things down, not up and it should be still accelerating at that time, and there is a constant speed at which it accelerates. Like i said there, I forgot that part, but the rest should be decent. There's also some maximum that it can accelerate at, nevermind there is a maximum velocity it can achieve. Orphic, just uh write down some number there I guess I can't remember.
August 28, 2013
Orphic

47.5 was within 10% of the answer.

The only negative acceleration you should have to factor in is gravity using -9.8m/s^2
August 28, 2013
BlueAo

If you are already familiar with concepts of acceleration and motion I could try to simply explain it to you.

Even though it has been quite a while since the last time I've done such problem solving it should be no biggie.
Gravity and Angle (and enviromental resistance aka force) play a key role, other than that its pure logic.

Now if you don't mind, its like 4 am and I would like to get a few hours of sleep before a "new" day :/
August 28, 2013
Orphic

Gnight Blue-kun.
August 28, 2013
Link

Quote:

Originally Posted by Ptolemy

47.5 was within 10% of the answer.

The only negative acceleration you should have to factor in is gravity using -9.8m/s^2

But that wasn't an answer, that was a number to find the answer :P
August 28, 2013
Orphic

I played around with numbers and got that. Sue me.

How about this one: A doctor is preparing a syringe for a patient. He angles the syringe directly upwards and the liquid shoots out at 1.4 m/s. How long until the liquid reaches the height of the syringe again? What is the maximum height achieved by the liquid?

Thankfully, gravity is literally the only negative acceleration factor you have to account for. Air resistance and **** like that hasn't been discussed yet.
August 28, 2013
Lawl

Quote:

Originally Posted by Ptolemy

How about this one: A doctor is preparing a syringe for a patient. He angles the syringe directly upwards and the liquid shoots out at 1.4 m/s. How long until the liquid reaches the height of the syringe again? What is the maximum height achieved by the liquid?

http://images.sodahead.com/profiles/...519235208.jpeg

What I say to 90% of all math and the question you posted.
August 28, 2013
Orphic

Quote:

Originally Posted by Lawl

http://images.sodahead.com/profiles/...519235208.jpeg

What I say to 90% of all math and the question you posted.

My douchey physics teacher cares :'|
August 28, 2013
Antalar

Quote:

Originally Posted by Ptolemy

I played around with numbers and got that. Sue me.

How about this one: A doctor is preparing a syringe for a patient. He angles the syringe directly upwards and the liquid shoots out at 1.4 m/s. How long until the liquid reaches the height of the syringe again? What is the maximum height achieved by the liquid?

Thankfully, gravity is literally the only negative acceleration factor you have to account for. Air resistance and **** like that hasn't been discussed yet.

Quote:

Originally Posted by Ptolemy

A man throws a ball into the air. After 0.8 seconds it reaches a height of 38 feet. What was the initial velocity? How long did it take for the ball to reach 19 feet and what was the velocity at the time? Ignore air resistance.

i.....i dont know!!

i am a ma....person of science!...god damnit i hate physics!!
August 28, 2013
Abra

Quote:

Originally Posted by Ptolemy

I played around with numbers and got that. Sue me.

How about this one: A doctor is preparing a syringe for a patient. He angles the syringe directly upwards and the liquid shoots out at 1.4 m/s. How long until the liquid reaches the height of the syringe again? What is the maximum height achieved by the liquid?

Thankfully, gravity is literally the only negative acceleration factor you have to account for. Air resistance and **** like that hasn't been discussed yet.

Did you learn the 3 kinematic equations for constant acceleration?

Spoiler: Show

http://octave.1599824.n4.nabble.com/...2529/KE1-3.jpg

If so, all you do is pick the one you need and plug in the numbers.

Show 15 post(s) from this thread on one page