Science & Mathematics - 8 October 2007

1. a ball is thrown into the air with an initial velocity of 35m/s. what is the maximum height the ball reached?

2. a plane experiences a constant acceleration. if the plane starts from rest and needs to reach a velocity of 50m/s to take off and the runway is only 500 meters long what is the acceleration needed for the plane to take off?

use the following equations:
-V=intial V+at
-X=initial X+initial V(t)+1/2at^2
-V^2=initial V^2+2a(X-initial X)

2007-10-08 15:47:30 · 1 answers · asked by anynomous 1 in Physics

At the surface of Jupiter's moon Io, the acceleration due to gravity is 1.81 . A watermelon has a weight of 52.0 at the surface of the earth. In this problem, use 9.81 for the acceleration due to gravity on earth.

2007-10-08 15:46:25 · 3 answers · asked by Natiphy2007 1 in Physics

8.9 + 1.2 ( 3a-1)=14.9

how to you solve it in steps
i am actually understandning these problems now, but i'm still have trouble with the steps

2007-10-08 15:45:25 · 5 answers · asked by Anonymous in Mathematics

Shaunice has 36 feet of fence to put around her rectangular flowerbed. How long and how will the flowerbed have to be so that she has 72 square feet of area to plant flowers?

2007-10-08 15:44:26 · 2 answers · asked by Anonymous in Mathematics

Why do moths have their wings covered in powder?
Why does removing the wing powder coating render them unable to fly?
If lost, can the coating be re-installed to restore flight ability?
Why do butterflys not need such dust on their wings?

2007-10-08 15:36:39 · 3 answers · asked by malancam55 5 in Zoology

2007-10-08 15:32:31 · 3 answers · asked by Anonymous in Weather

PLease give me some examples and tell me I need it for math class. Thanks

2007-10-08 15:32:30 · 8 answers · asked by D 2 in Mathematics

i know how to factor but i'm not a genius at it already so can a genius help me how to do this problem step by step. once i see how to do it i can catch on. i have ten problems like this but i only need one example- here it goes math genius 10points to the best answerer.

I NEED HELP ON THIS ONE ALSO

x^5+x^3-6x
factor completely

2007-10-08 15:32:19 · 3 answers · asked by Anonymous in Mathematics

I am currently living in a place that is haunted. There are ghosts/spirits that wander around from time to time. Is there I way I can communicate with them or at least get there attention?

2007-10-08 15:31:21 · 22 answers · asked by Yahoo Sucks 5 in Paranormal Phenomena

Can some type of heating be used to speed-evaporate large quantities of water into the air? This water would be carried by the clouds, to wherever the clouds go. Wherever the clouds rain down, can be a pumping station, perhaps. We could use quantative evaporation (via solar or other means) and wind to transport water over large distances?

2007-10-08 15:31:02 · 4 answers · asked by piqchure2 1 in Weather

Did you do work? To answer this question, consider whether you applied a force parallel to the displacement of the moving end of the rubber band.

I got this part right it was simple but I just dont understand this part

Consider how the force applied to stretch the rubber band feels as you stretch it. Order from least to most force applied. (If B is the least, then A, then C, enter BAC.)

A) At the beginning of the stretch.
B) In the middle of the stretch.
C) At the end of the stretch.

2007-10-08 15:29:42 · 1 answers · asked by Anonymous in Physics

I really just need a simple explanation, like is it because of it's depth or it's temperature

2007-10-08 15:25:45 · 6 answers · asked by Jenna 1 in Earth Sciences & Geology

Scientific theories, not religious.
Feel free to only offer one if you dont know more than that
thanks

2007-10-08 15:22:39 · 3 answers · asked by tyler 2 in Biology

I don't need answers I am just stuck on how to formulate the correct equation

The magnitudute of each force is 164 N the fore on the right is applied at an angle of 44 degrees. he mass of an object is 16 kg
The coefficient of friction is .268 the acceleration of gravity is 9.8m/s/s

Find the resulting acceleration

the second problem


An 863N crate is being pushed across level floor by a force of 313 N at an agle of 21 degrees above the horizontal. The coefficient of kinetic friction between the crate and the floor is .2 the acceleration of the gravity is 9.81 m/s/s

What is the acceleration of the box?


Thank you for any help

I DO NOT NEED AN ANSWER, JUST HOW WOULD I MANIPULATE THE EQUATIONS TO SOLVE THESE PROBLEMS THANK YOU

2007-10-08 15:20:19 · 2 answers · asked by Anonymous in Physics

1/10 + 1/20 = 1/? Write your answer as a common fraction reduced to lowest terms.

2007-10-08 15:16:18 · 16 answers · asked by Anonymous in Mathematics

a large cube (mass = 24 kg) is being accelerated across a horizontal frictionless surface by a horizontal force P. A small cube (mass = 2.6 kg) is in contact with the front surface of the large cube and will slide downward unless P is sufficiently large. The coefficient of static friction between the cubes is 0.71. What is the smallest magnitude that P can have in order to keep the small cube from sliding downward?

i know the equation is P-Fn=ma

Fn is the natural forcei know that you are supposed to add the natural force some where but im not sure where.

that is as far as i could get with this problem. see, i really did try to do it. i just can't finish it. please, PLEASE help me. i really am trying!

2007-10-08 15:08:17 · 3 answers · asked by Elizabeth 3 in Physics

2007-10-08 15:08:11 · 10 answers · asked by tyler 3 in Medicine

I don't know if this is a solvable question or not but here's the question.

A rock is thrown directly upward from the edge of the roof of a building that is 56.3 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Take the acceleration due to gravity to have magnitude 9.80 m/s^2 and neglect air resistance. With what speed was the rock thrown?

it just seems like i'm not given enough information. any suggestions on how to figure this out.

2007-10-08 15:07:26 · 1 answers · asked by shadoyaj 4 in Physics

ok I have a generator and a resistor connected to a transformer. 30 ohm resistor with 11 loops on the transformer. the generator oscillates between 500 and -500 v and has 5 loops.

what is the average power on the resistor

2007-10-08 15:04:09 · 1 answers · asked by cheski88 1 in Physics

no web site please

2007-10-08 15:03:54 · 1 answers · asked by Becker14 1 in Chemistry

Sand is falling off a conveyor onto a conical pile at the rate of 15 cubic feet per minute. The diameter of the base of the cone is approximately twice the altitude. At what rate is the height of the pile changing when it is 10 feet high?


Please answer soon i have a test tomorrow!

2007-10-08 15:02:39 · 1 answers · asked by Rahul R 2 in Mathematics

2007-10-08 15:01:10 · 1 answers · asked by shauna s 1 in Chemistry

2007-10-08 15:00:50 · 5 answers · asked by Sabine 6 in Engineering

2007-10-08 14:59:39 · 1 answers · asked by Catharine W. Dulaney 2 in Chemistry

2007-10-08 14:57:31 · 1 answers · asked by Anonymous in Medicine

A student completes two trials of an experiment and calculates the mass percent magnesium in the product as 62.39%. Assuming that the product is a mixture of MgO and Mg3N2, calculate the mass percent of MgO in the synthesized product. (Hint: calculate the theoretical percent magnesium for comparison in both the MgO and Mg3N2.)

2007-10-08 14:56:20 · 1 answers · asked by Brookey 2 in Chemistry

A child in danger of drowning in a river is being carried downstream by a current that has a speed of 2.50 km/h. The child is 0.600 km from shore and 0.800 km upstream of a boat landing when a rescue boat sets out.

(a) If the boat proceeds at its maximum speed of 17.0 km/h relative to the water, what heading relative to the current should the pilot take?
__________° relative to the direction of the current
(b) What angle does the boat velocity make with the current?
__________° relative to the direction of the current
(c) How long does it take the boat to reach the child?
__________s



I have no idea how to do this. Could anyone help me?
Thanks.

2007-10-08 14:49:46 · 1 answers · asked by The Rationalist 2 in Physics

I thought I knew how to do it, but I can't get the right answer...

Magnesium burns in air to produce magnesium oxide, MgO, and magnesium nitride, Mg3N2. Magnesium nitride reacts with water to give ammonia.


Mg3N2(s) + 6H2O(l) ==> 3Mg(OH)2(s) + 2NH3(g)


What volume (in L) of ammonia gas at 24oC and 743 mmHg will be produced from 4.37 g of magnesium nitride?

2007-10-08 14:49:15 · 1 answers · asked by Anonymous in Chemistry

A 50% efficient hydroelectric power plant generates electricity from water falling a height of 110 m and at a rate of x kg/s. If the maximum possible power output of the plant was 27.0 MW, what is x?

2007-10-08 14:43:37 · 4 answers · asked by beer drinkers 2 in Engineering

A flowerpot is dropped from a balcony of an apartment 28.5m above the ground. At a time of 1.00s after the pot is dropped, a ball is thrown vertically downward from the balcony one storey below, 26.0m above the ground. The initial velocity of the ball is 12m/s (down). Does the ball pass the flowerpot before striking the ground? If so, how far above the ground are the two objcts when the ball passes the flowerpot?

2007-10-08 14:43:03 · 2 answers · asked by mahdi_end2006 2 in Physics