**** physics....

[bk12321 10+ year member]

Alright so now that I kinda am getting calc II... for the moment (by the way we are on volume of revolutions and the shits crazy)... physics is kicking my ***. I can get half of this problem, but I dont know how to finish. If someone could help I'd appreciate it. This semester sucks, ive never done so much work in my life, last year in college was 100x easier.

The problem is:

In an indoor domed baseball stadium the ceiling is designed so that a hit ball could not possibly strike the ceiling. Assume a major league fastball max speed of 95.0 miles/h and that the wooden bat might decrease this to 80.0 miles/h. Assume that the ball leaves the bat at a height of 1.00 m above the playing field.

a) Determine the minimum ceiling height so thata major league pop-up (that is, when the ball leaves the bat travelling straight up) does not hit the ceiling.

b) in a real game, a pop-up comes within 10m of this ceiling height. What was the ball's speed as it left the bat?

thanks so much... this is one of 5 quiz problems we have to turn in tomorrow and its the only one I dont get. I think you have to solve for one kinematic equation and plug in but I dont know lol.

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[bose301s 5,000+ posts]

Vi is 80mph, acceleration is gravity in the downward direction. From there its easy. Use this eqn. vf^2 = vo^2 + 2ad, vf=0, vo=80mph, a is the acceleration due to gravity and d is what you are solving for, the same equation can ve used for part b.

As for the problem, it's BS as a ball off the bat has been know to be upwards of 125mph, your teacher is a moron.

 

[faulkton 5,000+ posts]

A) really fukin' high

B) really fukin' fast

 

[dragnix 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif it's theoretical man

 

[jblayz1 10+ year member]

Mr. Spock would have a logical answer. But then again, baseball wouldn't make any sense to him.

 

[faulkton 5,000+ posts]

http://beconfused.com/images/2007/04/Homework-I-would-check-to-see-if-it-had-a-******.jpg

 

[Flipx99 5,000+ posts]

^^

lol

 

[faulkton 5,000+ posts]

flip Thursday is the day i present my paper at the GPSA conference.

Oh noes!

 

[bk12321 10+ year member]

I have 20 ****ing circular motion problems due tomorrow and I can't get some of them... anyone who can help, its greatly appreciated. Ive been to the physics resource center twice to get help, and there are never any TA's in there.

problem 11:

Two wires are tied to the 320g sphere pictured. The sphere revolves in a horizontal circle at a constant speed of 6 m/s. What is the tension in each of the wires?

You just have to find the tension force in each wire. I solved it but i'm getting the wrong answer //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif. This one seems to be the easy one but I just can't get the right answer so im dumb.

 

[bk12321 10+ year member]

oh and all I really need is for somebody to get me started, u dont have to do the whole thing if u dont want to

 

[bk12321 10+ year member]

I have 20 ****ing circular motion problems due tomorrow and I can't get some of them... anyone who can help, its greatly appreciated. Ive been to the physics resource center twice to get help, and there are never any TA's in there.
problem 11:

Two wires are tied to the 320g sphere pictured. The sphere revolves in a horizontal circle at a constant speed of 6 m/s. What is the tension in each of the wires?

Finally figured out the answer to the other 2, anyone care to help me with this problem???

circular motion FTL

 

[ToyTundra 10+ year member]

I'm probably too late:

find the distance from the sphere to the rod using trig. You know the radius, mass, tangential velocity so you should be able to calculate the outward force (-centripital acceleration*mass?)

Use trig and x,y components to calculate the tension in each rope. They should be equal. This is all assuming gravity is negligable.

 

[bk12321 10+ year member]

I'm probably too late:find the distance from the sphere to the rod using trig. You know the radius, mass, tangential velocity so you should be able to calculate the outward force (-centripital acceleration*mass?)

Use trig and x,y components to calculate the tension in each rope. They should be equal. This is all assuming gravity is negligable.

problems are due at 11 so no ur not too late

I can get the net force but from there I dont know if what im doing is right to find the x and y components in order to find the tension of each rope

 

[Ruthless Pastor 10+ year member]

"Physics makes us all its' *****es"

-Of Montreal

 

[bk12321 10+ year member]

"Physics makes us all its' *****es"
-Of Montreal

it really does... ive been workin on this for so ****ing long today