Science & Mathematics - 4 November 2007

2007-11-04 01:32:31 · 8 answers · asked by Jenny D 1 in Mathematics

I've calculated the drag constant for a tennis ball (v^2 * -6.15x10^-4) and we know that vf=vi+at and df=1/2at^2+vit+di. But how would I be able to calculate the velocity and displacement at any given time, if I encompassed air resistance?
To anyone who wants to know, you can find the force of drag at any given time by: (vi+at)^2 or (-9.8t+vi)^2, where down is negative, and multiply that by the drag constant. So if you through a ball UP in the air at 30 m/s, the drag at any given time would be: f(x)=(-6.15x10^-4)*(-9.8t+30). So I want to know how to put this together in one function to find the displacement or velocity at any given point, including air resistance. Thanks!

2007-11-04 01:28:02 · 2 answers · asked by Sheen J 1 in Physics

the greatest possible acceleration and deceleration that a car can have r a and 2a rsptvly,and its max speed is v.Find the minimum time in which the car can cover a dist = s.

2007-11-04 01:25:59 · 1 answers · asked by anil p 1 in Physics

2007-11-04 01:25:23 · 1 answers · asked by Anonymous in Chemistry

Suppose a person has propranolol before severe exercise, how will it change his endurance to exercise ?

2007-11-04 01:24:48 · 4 answers · asked by feletoon 2 in Medicine

What time is it right now in the united states? i need to know because of daylight savings.

ps. Plz state the state that your in and the time.

2007-11-04 01:22:37 · 6 answers · asked by JustLiz 2 in Astronomy & Space

Here goes:
Both Winifred and Winston collect model helicopters. Between them they have 200. If Winifred sold Winston 50, then Winston would have 4 times as many as Winifred. How many does Winifred have.

The working out must have an algebraic thingy in it it e.g winifred could be a, and winston b, etc.

2007-11-04 01:22:26 · 8 answers · asked by Anonymous in Mathematics

For these questions I have got different answers so I wanted to know which were correct.

1. The acceleration due to gravity is
A. Always directed toward the earth and therefore negative
B. Positive when velocity is positive
C. Negative when velocity is negative
D. B and C
E. None of these

(I got A and E)

18. Mac and Tosh are arguing in the cafeteria. Mac says that if he throws his jello with a greater speed it will have a greater inertia. Tosh argues that inertia does not depend upon speed, but rather upon mass. With whom do you agree and why?
A. Mac because greater speed means greater inertia.
B. Tosh because inertia depends upon acceleration.
C. Tosh because mass is a measure of inertia.
D. Mac because greater speed means greater force and force is directly proportional to inertia.
E. None of these

(I got C and A)

20. If we divide a Newton by a square meter the units that result are units of
A. Speed
B. Force
C. Mass
D. Acceleration
E. Pressure

2007-11-04 01:17:46 · 5 answers · asked by Joe T 1 in Physics

C6H4(OH)2(aq) + H2O2(aq) C6H4O2(aq) + 2 H2O(l)

Calculate H for the above reaction from the following data.
C6H4(OH)2(aq) C6H4O2(aq) + H2(g) H = +177.4 kJ
H2(g) + O2(g) H2O2(aq) H = -191.2 kJ
H2(g) + 1/2 O2(g) H2O(g) H = -241.8 kJ
H2O(g) H2O(l) H = -43.8 kJ

Can i get a step by step demo please?

2007-11-04 01:16:25 · 1 answers · asked by summitgirl06 1 in Chemistry

2007-11-04 01:15:39 · 4 answers · asked by Tracy 1 in Astronomy & Space

2007-11-04 01:13:36 · 4 answers · asked by aznpenguin901 1 in Astronomy & Space

And what kind of traits (superior or inferior intellect, appearance, etc) will the evolved species from homo sapiens have?

2007-11-04 01:11:43 · 5 answers · asked by Pansy 4 in Biology

1,2,4,3...

2007-11-04 01:06:44 · 4 answers · asked by Anonymous in Mathematics

2007-11-04 01:05:54 · 5 answers · asked by mrudshyam 1 in Other - Science

I forgot how to multiply a decimal by a whole number how do I do it helppppppppppppp!!!!!

2007-11-04 01:05:41 · 6 answers · asked by Anonymous in Mathematics

i have a quiz tomorrow and need some help

1. write the standard form of the equation of the line that is parallel
to the graph of y=2x -3 and passes through the point at (1,-1)

2. write the standard form of the equation of the line that is perpendicular to the graph of y=2x -3 and passes through the point at (6,-1)

2007-11-04 01:05:29 · 2 answers · asked by Anonymous in Mathematics

would you prefer not to observe daylight savings time and why? I have lived in the Midwest most of my life and only when I lived in Northern Indiana, did I not observe daylight savings time. Now I live in an area where it is observed. I don't like it.

2007-11-04 01:02:44 · 7 answers · asked by ≤ Flattery Operated © 7 in Geography

when the United States only constitutes part of America?

2007-11-04 01:01:28 · 24 answers · asked by Maz T 3 in Geography

I exist both in the real world and in fantasy. In the real world, I can walk on water, in fantasy, if you look into my eyes, you will instantly die. I am a lizard. Who am I?

2007-11-04 01:59:58 · 10 answers · asked by Guerilla 5 in Zoology

Greg worked 36 hours this week. This is 3 more than twice the # of hours Darryl worked. Which equation could you use to find how many hours Darryl worked?
A. 36 = 2x + 3
B. 36 = 2x -3
C. 36 = 2(x+3)
D. 36 = 3(x+2)

2007-11-04 01:59:33 · 4 answers · asked by Karissa F 1 in Mathematics

During my first year of college I was an Aerospace Engineering major. I took Calculus, Physics, and Chemistry.

I had an easier time with Calculus than I had with Trigonometry and Math Analysis in high school. Are there any mathematicians out there that agree with me that learning Calc is easier?

Many thanks,
C.L.

2007-11-04 01:57:48 · 4 answers · asked by Ccl471 1 in Mathematics

solve

2007-11-04 01:51:39 · 13 answers · asked by Karissa F 1 in Mathematics

This question is almost a debate I realise that. It will not in all likelihood change any minds, but may influence the minds of those who are currently suffering cognitive dissonance regarding the conflicts between Evolutionary theory and Creationist theory.

The crux of the argument to me seems to be whether 'faith' trumps 'reason' or vice versa. http://www.fstdt.com illustrated to me the gulf between those who accept the holy book of any religion as a tool for truth and those who accept scientific principle as a tool for truth.

The quote I read saying 'You honestly believe the world was created over millions of years and not six days?' just summed up the seemingly unassailable wall between the two world views, obviously the opposite could just as sincerely be said as an argument against creationism.

So, how do you KNOW which trumps which, Faith or Reason? How can we know the answer to this question? Are faith and reason totally, mutually, incompatible?
Yours hopefully,
Yuk

2007-11-04 01:50:41 · 11 answers · asked by Anonymous in Biology

in measuring of atmospheric pressure of a specific station , it seems "QFE" parameter as actual pressure is enough. Why we need "QNH" as reduced to standard condition or "QFF"as reduced to sea altitude is necessary? it seems they are not useful or practicable information. what is meant if e.g. "QNH" is other than 1013 hpa(milibar)?

2007-11-04 01:50:08 · 2 answers · asked by nader 1 in Weather

if f"(x) = 3/sqrt(x) and f'(4) =7 then f(x) equals

2007-11-04 01:47:16 · 6 answers · asked by Anonymous in Mathematics

A woman is reported to have fallen 144 ft from the 17th floor of a building, landing on a metal ventilator box, which she crushed to a depth of 18 inches. She suffered only minor injuries. Neglecting air resistance, calculate (a) the speed of the woman just before she collided with the ventilator, (b) her acceleration while in contact with the box, and (c) the time it took to crush the box. Then assume that the woman fell on a much “harder” surface which only crushed 2 inches, redo the calculations, and use your answers to explain why the woman was “happy” to land on the ventilator box.

2007-11-04 01:44:55 · 1 answers · asked by Anonymous in Physics

Dissolved oxygen in water

2007-11-04 01:44:19 · 3 answers · asked by Anonymous in Earth Sciences & Geology

i cant solve these three problems can anyone help out?? Tnx!!!
Arigatogozaimasu!!!

What voltage is required to store 7.2 x 10-5 C of charges on the plates of a 6.0 F capacitor?

One farad is a large capacitance. To see just how large, determine the area of each plate of an empty, one farad parallel plate capacitor whose plate separation is one meter. Express your answer in square miles.

A parallel plate capacitor has a capacitance of 7.0 F when filled with a dielectric. The area of each plate is 1.5 m2 and the separation between the plates is 1.0 x 10-5 m. What is the dielectric constant of the dielectric?

2007-11-04 01:41:45 · 2 answers · asked by Anonymous in Physics

2007-11-04 01:38:31 · 9 answers · asked by Nicole D 1 in Mathematics

How can you prove that there exists a real number c independent of n such that

a^n >= c*n^(k+1)

where a is a positive real, k is a positive integer, and c is independent of n, so that it is true for n=1,2,3,...

I've tried letting a=1+b and using the binomial expansion and it seems to help, but i'm still getting stuck. i think it will be to do with sequences and limits etc as well.

thanks

2007-11-04 01:37:46 · 1 answers · asked by mongrel73 1 in Mathematics