# Stefan

Popular questions and responses by Stefan
1. ## 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

2. ## history

i need help on the Lesson 7: Unit Test CE 2016 Social Studies 8 A Unit 2: The Revolutionary Era

3. ## Physics

A 2.40 m length of wire is held in an east-west 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

4. ## 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

5. ## 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

6. ## 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?

7. ## geography

why is Israel the only country in the region that qualifies as a developed nation?

8. ## 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)=-1.5|T-8|+9. which analysis of the formula is true? A. Skip is 9 feet from the wall and the ball will

9. ## 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

10. ## 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.

11. ## Physics

In one cycle a heat engine absorbs 530 J from a high-temperature reservoir and expels 310 J to a low-temperature 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

12. ## History

What are the main factors that have affected the economic development in the Middle East? Explain the economic stagnation in the region.

13. ## 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,

14. ## 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.

15. ## 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

16. ## 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?

17. ## math

come si fanno le frazioni di un numero

18. ## 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 first-order minimum along a wall 6.70

19. ## 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

20. ## 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.

21. ## 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.

1. ## maths

13

posted on February 11, 2020
2. ## maths

100

posted on February 11, 2020
3. ## maths

50

posted on February 11, 2020
4. ## Natural Disasters

for connexous 2 is d but every thing is right but all the answers are 1. b 2. d 3. a

posted on October 1, 2019
5. ## history

check

posted on August 30, 2019
6. ## history

1. b 2. d 3. a,c 4. a 5. b 6. b 7. c 8. d 9. c 10. a,d 11. d 12. c 13. c 14. a 15. b 16. d 17. d 18. b 19. c 20. and then i could do this one on my own

posted on August 30, 2019
7. ## history

here they are

posted on August 30, 2019
8. ## history

well i did answer them and hopefully i got some right

posted on August 30, 2019
9. ## history

ok

posted on August 30, 2019
10. ## 10th

the glass stirring rob submerge the copper coil into the silver nitrate AgNO3

posted on January 5, 2018
11. ## help with one question please!!

Thanks Damon as always.

posted on December 12, 2017
12. ## chemistry

42... It's always 42

posted on March 31, 2016
13. ## History

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

posted on March 20, 2016
14. ## maths

ans x=130 and y=145 is it right pls help me

posted on January 25, 2016
15. ## maths

i don't know pls help me

posted on January 25, 2016
16. ## maths

15x + y = 0 ---------- 1 x1 x + y = 275 -------- 2 x15 15x + y = 0 15x +15y = 4125 - - - ---------------------- 0 -14y = -4125 y = -4125 -14

posted on January 25, 2016
17. ## maths

15x + y = 0 x + y = 275

posted on January 25, 2016
18. ## maths

PQR is an interior triangle within triangle PST. QR runs parallel to ST.

posted on July 8, 2014
19. ## Physics

posted on December 4, 2010
20. ## Physics

By taking 3.87E9/4.18 then dividing it by the flow rate of the water (1.0E6 kg/s = 1.0E9 g/s)

posted on December 4, 2010
21. ## Physics

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%.

posted on December 4, 2010
22. ## math

655555

posted on June 17, 2008