Posts by stefan
Total # Posts: 33

geography
why is Israel the only country in the region that qualifies as a developed nation? 
History
What are the main factors that have affected the economic development in the Middle East? Explain the economic stagnation in the region. 
math
Skip is practicing tennis serves against a wall. The distance between Skip and the tennis ball, in feet, at any time T, measured in seconds, is D(T)=1.5T8+9. which analysis of the formula is true? A. Skip is 9 feet from the wall and the ball will return to him in 1.5 ...  These questions didn't come from the the text. The teacher was saying them out loud and we were supposed to write them down. He got them from our test. I'm confused with the third question too, my step dad said the same thing. I think I found the answers for the 4th ...

History
I've been looking for the answers to questions on my study guide for a test I will have for a couple hours and I got a lot of them. However, there are some that I still have a hard time finding. Here are the questions. If I can be told even some of these, that would be ... 
maths
out of 10 litre a milkman sells some milk at the rate of Rs 15 perlitre and some at the rate of 12 per litre . He gets Rs 141 on selling it. Find the quantity of milk he sold at each rate.  ans x=130 and y=145 is it right pls help me
 i don't know pls help me
 15x + y = 0  1 x1 x + y = 275  2 x15 15x + y = 0 15x +15y = 4125     0 14y = 4125 y = 4125 14
 15x + y = 0 x + y = 275

maths
suresh scored 15 mareks more than ramesh in maths.if the sum of their marks in maths is 275.write the statement in linear equation in two variables  PQR is an interior triangle within triangle PST. QR runs parallel to ST.

maths
QR is parallel to ST and PQ:QR = 2:1. Given the area of triangle PST is 18cm2, the area of triangle PQR in sq cm is? 
Chemistry (My previous post lacked something)
Question: At STP propane (C3H8) burns in oxygen to form 2.15L of carbon dioxide and water. The question is in 4 parts. I just need the first: a)What mass of oxygen is necessary for this reaction? So far I've got 2.15 L x 1 mole /22.4 L But when I try to do the mole ratio, ... 
Chemistry
So I have the balanced equation: c3H8 +502 = 3C02 +4H20 Question: At STP propane (C3H8) burns in oxygen to form 2.15L of carbon dioxide and water. So I've got 2.15 L x 1 mole /22.4 L But when I try to do the mole ratio, I don't know what to do since the 2.15 L is of ...  Thanks Damon as always.

Science
a sample of an unknown metal has a mass of 21.6g and a volume of 8.00cm^3 . calculate the density of the unknown metal 
math
come si fanno le frazioni di un numero 
Physics
Microwaves of wavelength 4.50 cm enter a long, narrow window in a building that is otherwise essentially opaque to the incoming waves. If the window is 36.5 cm wide, what is the distance from the central maximum to the firstorder minimum along a wall 6.70 m from the window? 
Physics
A 2.40 m length of wire is held in an eastwest direction and moves horizontally to the north with a speed of 15.1 m/s. The vertical component of Earth's magnetic field in this region is 40.0 µT directed downward. Calculate the induced emf between the ends of the ... 
Physics
An eight turn coil encloses an elliptical area having a major axis of 40.0 cm and a minor axis of 30.0 cm. The coil lies in the plane of the screen and has a 6.10 A current flowing clockwise around it. If the coil is in a uniform magnetic field of 2.07 104 T directed toward ... 
Physics
An eight turn coil encloses an elliptical area having a major axis of 40.0 cm and a minor axis of 30.0 cm. The coil lies in the plane of the screen and has a 6.10 A current flowing clockwise around it. If the coil is in a uniform magnetic field of 2.07 104 T directed toward ...  the glass stirring rob submerge the copper coil into the silver nitrate AgNO3

College Physics
A charge of 3.10 nC and a charge of 6.65 nC are separated by a distance of 80.0 cm. Find the position at which a third charge of +7.10 nC can be placed so that the net electrostatic force on it is zero. 
College Physics
A charge of 3.10 nC and a charge of 6.65 nC are separated by a distance of 80.0 cm. Find the position at which a third charge of +7.10 nC can be placed so that the net electrostatic force on it is zero.  Thanks for your help! I got the correct answer
 By taking 3.87E9/4.18 then dividing it by the flow rate of the water (1.0E6 kg/s = 1.0E9 g/s)
 Thanks for your help. For the answer I got it to be 0.925837321 by following your directions. When I submitted it to my online homework it said the answer was wrong and off by more than 10%.

Physics
A nuclear power plant has an electrical power output of 1200 MW and operates with an efficiency of 31%. If excess energy is carried away from the plant by a river with a flow rate of 1.0 x 10^6 kg/s, what is the rise in temperature of the flowing water? 
Physics
In one cycle a heat engine absorbs 530 J from a hightemperature reservoir and expels 310 J to a lowtemperature reservoir. If the efficiency of this engine is 55% of the efficiency of a Carnot engine, what is the ratio of the low temperature to the high temperature in the ... 
question...biographies
Which is the MOST important literary element in biographies? A.Plots B.Characters C.Settings D.Point of view I believe is characters...but I just want to make sure with some one.  42... It's always 42
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