# Posts by sydney

Total # Posts: 506

**Chemistry**

Can you please help me write the oxidation and reduction half reactions represented in each of these redox equations, and help me write the half reactions in net ionic form if they occur in aqueous solution. 1) PbO(s) + NH3(g) --> N2(g) + H2O(l) + Pb(s) 2) I2(s) + Na2S2O3(...

**chemistry**

/Users/Sydneyvanalphen/Desktop/Screen Shot 2015-08-18 at 3.21.30 PM.png hi i need help with this homework problem I don't get how they are getting the answer 75?

**Chemistry**

All Brønsted-Lowry acids A. are aqueous solutions. B. can act as Arrhenius acids. C. donate protons. D. all of the above I got C but could it be D?

**Chemistry**

Can you please explain to me how you would regulate the pressure to favor the products in the this equilibrium system. MgCO3(s)--><-- MgO(s)+CO2(g) Thank you

**Chemistry**

Can you please explain to me how you would regulate the pressure to favor the products in the this equilibrium system. MgCO3(s)--><-- MgO(s)+CO2(g) Thank you

**chemistry**

can you please explain to me why a common ion lowers the solubility of an ionic compound

**algebra 1**

How many solutions are there to the system: y=1+2x+x^2 y=1-x Write your answer as an integer.

**algebra**

Suppose Paul kicks a soccer ball straight up into the air with an initial velocity of 96 feet per second. The function f(x) = -16t2 + 96t gives the height, in feet, of the soccer ball after t seconds.Show all work to find the axis of symmetry algebraically. You must show all ...

**Chemistry**

How mush CaCl2, in grams, is needed to make 2.0 L of a 3.5M solution? g CaCl2 = (2.0L) *( 3.5 mol Cl-/1L) * (1mol CaCl2/ 2mol Cl-) *( 110.98 g CaCl2/ 1 mol CaCl2) = 5.549 g CaCl2 i don't think i did any of this right

**DragonWings LA**

?? Is right

**Algebra 1**

17 dimes 12 nickels

**Physics**

Suppose the cross sectional of the tube is 0.05 cm2, what would be the volume (a) during the lowest pressure in the experiment? (b) during the highest pressure? (c) at the atmospheric pressure?

**Precalculus**

Ah, that makes sense! I always forget the trig addition formulas, thank you!

**Precalculus**

Evaluate: tan(arcsin(8/17)+ arctan(4/3)) I understand that I have to make triangles out of the values given-- with 15 being the other side of the 17 and 8 triangle, and 5 being the other side of the 4 and 3 triangle. I'm not sure where to go on from there, though.

**Math 141**

A pair of fair 6-sided dice is rolled. What is the probability that a 3 is rolled if it is known that the sum of the numbers landing uppermost is less than or equal to 6?

**Algebra**

Jan received $2,200 from her aunt as a birthday gift. She decided to put the money in an account to save for college. The account has a fixed interest rate of 7.7%, compounded annually. How much money will be in the account after five years?

**science**

ways to help farmers increase agricultural productivity

**science**

if .38 kJ of heat is added to 19.6 grams of ice at -12.0 degrees celsius, what will be the final temperature?

**algebra2**

Confused

**Chemistry**

It suggests that those transition metals have lost there 's' orbital

**Math**

Peter has money in two savings accounts. One rate is 9% and the other is 11%. If he has $400 more in the 11% account and the total interest is $117, how much is invested in each savings account?

**Math**

How do you graph a rectangle and find its area if: A(1,-3) B(1,3) C(-9,3) D(-9,-3)

**Chemistry**

What is the density (in mg/mL) of a H2S gas at 12.9 atm and 137 K?

**chemistry**

A 100.0 mL sample of 0.10 M NH3 is titrated with 0.10 M HNO3. Determine the pH of the solution before the addition of any KOH. The Kb of NH3 is 1.8 × 10-5. I thought that I would need a second volume to find the moles of NH3?

**Chemistry**

Silver carbonate [AgCar] has a density of 6.077 g/cm3. Calculate the mass (in fg) of carbon atoms [C] present in a AgCar crystal that has a volume of 457.6 Å3.

**Physics**

Jeff’s basketball falls into a pond. There is no wind and the water is still. Jeff wants to get the ball. He throws a rock into the pond, which hits water at 2 ft behind the ball from Jeff’s view. What will happen to the ball?

**Social Studies**

ok thank you

**Social Studies**

Why is diplomacy a key part of U.S. foreign policy? Because it helps prevent wars and helps countries settle issues and work together I really don't know

**Social studies**

I am not supposed to use Wikipedia a s a source but maybe this will give me a better idea thanks

**Social studies**

How has the US economy changed over the past 50 years? I know it used to be mainly farming and manufacturing but now we have expanded on this with medical research technology, and education but I need help expanding this answer

**chemistry**

Experimental Molar Ratio of Copper in CuxOy

**College Physics**

Col. John Stapp led the U.S. Air Force Aero Medical Laboratory's research into the effects of higher accelerations. On Stapp's final sled run, the sled reached a speed of 284.4 m/s (632 mi/h) and then stopped with the aid of water brakes in 1.4 s. Stapp was barely ...

**English check**

Which principal part of the verb to teach appears in this sentence. Then she taught me how to cultivate rich and healthy soil and helped me identify which types of plants are best for the environment in my yard. past past participle present present participle I really don'...

**physics**

A mass pulled by a constant force accelerates from 10 cm/s to 40 cm/s in 5.5 s. A second force accelerates the same mass from rest to 105 cm/s in 15.0 s. If the first force is known to be 5.0 N, that what is the magnitude of the second force?

**Math**

How can Marco use the GCF to find ot how many tiles he has I all.

**physics**

Question: The swim portion of a triathlon takes place in a river and is an out-and-back course. The river has a steady current that is 0.400m/s and the athletes swim against the current for 750m before turning and swimming with the current for the second 750m. If one ...

**math**

Mega Mart collects sales tax equals to 1/16 of the retail price. Is the amount of tax collected proportional to the cost of an item before tax is added

**math**

Sales tax is 1/16. What is the tax when retail price is 16.

**Science Check PLEASE**

must be in connections? Your third one I don't think is right. I believe it is B. The rest look right!

**math problem solving**

50 and 5000

**Environmental Science**

Answer the questions about the following processes in the space provided below. You only need to indicate a process by its number. For each question list as many processes as apply. Process 1: 6 CO2 + 6 H2O → C6H12O6 + 6 O2 Process 2: C6H12O6 + 6 O2 → H2O + 6 CO2...

**Environmental Science**

H.B.D. Kettlewell observed that peppered moths in the forests of England were becoming darker in color over time. In addition, he observed that pollution had turned the tree trunks black. He thought it would be easy for birds to spot and capture light-colored moths resting on ...

**Just trying to help:)**

@You people are Stupid, Stop being a jerk, this is Jiskha, we only come here to learn, stop being negative and go away! Did'int your mother teach that saying? if you nothing nice to say don't say it at all.

**Science**

Ompalompa, your a true life saver. thank god for you!

**statistics**

a.) .5507 b.).3012 c.) .6321

**Chemistry**

A= ejected B=1->3 C=not absorbed D=1->2

**Math**

On joes farm there are 99 animals. There are four times as many cows as horses on the farm. There are twice as many horses as lives. How many horses, cows, and pigs are there?

**Physics**

A wooden block of mass m = 2.3 kg starts from rest on an inclined plane sloped at an angle 26 degrees from the horizontal. The block is originally located 1.9 m from the bottom of the plane. Assume the inclined plane is friction less. 1)What is the magnitude of the component ...

**math**

suppose x is a uniform random variable with c=40 and d=70. find the standard deviation of x

**math**

the diameters of ball bearings produced in a manufacturing process can be described using a uniform distribution over the interval 6.5 tp 8.5 millimeters. what is the mean diameter of a ball bearings produced in this manufacturing process?

**HELP**

Aba +bab --------- Ccc All posible values for all

**THEIF**

@Youarewelcome, Your cheating you moron, your taking bunny funnys work, you sick twisted person.

**english**

consider what you have learned about American history during the period 1860 to the early 1900s. how do the stories in unit 4 reflect what was going on in the country then?

**Math**

Ok thanks Steve. That makes a lot more sense now.

**Math**

Help! I don't know how to find the complement of a 30 degree angle! Please help me!

**Psychology**

How has the definition of social facilitation evolved

**physics. HELP**

A water balloon is thrown into the air and lands 30.0 meters away 1.8 seconds later. a. What was the speed of the balloon thrown (on the diagonal) b. At what angle was the balloon thrown with respect to the ground?

**physics. HELP**

A person has the ability to jump with an initial speed of 6.0 m/s at an angle of 35 degree with the ground. a. How long will the person be in the air? b. How far horizontally will the person travel?

**physics. HELP**

An athlete executing a long jump, leaves the ground at a 30 degree angle with the ground and travels 8.90 meters horizontally in 1.1 seconds. What was the takeoff speed of the athlete along the diagonal?

**physics. HELP**

I think the initially velocity is 0.

**physics. HELP**

A projectile is launched horizontally with a speed of 80.0 m/s. If the projectiles is launched above the floor, how long does it take the projectile to hit the floor?

**physics. HELP**

A projectile is launched horizontally with a speed of 80.0 m/s. If the projectiles is launched above the floor, how long does it take the projectile to hit the floor?

**physics**

A water balloon is thrown into the air and lands 30.0 meters away 1.8 seconds later. a. What was the speed of the balloon thrown (on the diagonal) b. At what angle was the balloon thrown with respect to the ground?

**physics**

A person has the ability to jump with an initial speed of 6.0 m/s at an angle of 35 degree with the ground. a. How long will the person be in the air? b. How far horizontally will the person travel?

**physics**

An athlete executing a long jump, leaves the ground at a 30 degree angle with the ground and travels 8.90 meters horizontally in 1.1 seconds. What was the takeoff speed of the athlete along the diagonal?

**physics**

A hunter aims directly at a target (on the same level) 170 meters away. If the bullet leaves the gun with a speed of 40 m/s, by how much will it miss the target? i.e. What is the vertical drop of the bullet?

**phyics**

A projectile is launched horizontally with a speed of 80.0 m/s. If the projectiles is launched above the floor, how long does it take the projectile to hit the floor?

**physics**

A 2.0 kg rock is dropped from the top of a building. I lands 14.0 seconds later. How tall was the building?

**Physics, HELP**

AN auto, moving too fast on a horizontal stretch of mountain road, slides off the road, falling into deep snow 43.9 meters below the road and 87.7 meters beyond the edge of the road. a. How long did the auto take to fall? b. How fast was it going when it left the road?

**physics. HELP**

Phil jumps off a high-diving platform with a horizontal velocity if 2.8 m/s and lands in the water 2.6 seconds later. a. How high is the platform b. How far out from where he jumped does he land?

**Physics... HELP**

A toy car runs off the edge of a table that is 1.225 meters high. If the car lands 0.400 meters from of the table, a. How long does it take for the car to fall? b. What is the horizontal velocity of the car?

**physics**

A dart player throws a dart horizontally at a speed of of 12.4 m/s. The dart hits the board 0.32 meters below the height from which it was thrown. How far away is the player from the board?

**physics**

A missile is fired horizontally with an initial velocity of 300 m/s from the top of a cliff 200.0 meters high. a. How long does it take the missile to reach the bottom the cliff? b. How far from the base of the cliff does the missile strike the ground?

**math**

A model rocket is launched with an initial velocity of 160 ft/s. The height, h, in feet, of the rocket t seconds after the launch is given by h = −16t2 + 160t. How many seconds after launch will the rocket be 350 ft above the ground? Round to the nearest hundredth of a ...

**Social study**

They came up with confederacies and governments. They all discussed different things until they figure out how to solve the problem. If tribes form together, they also go under one set of laws.

**Math**

state the amplitude, period, frequency, phase shift and vertical shift of each function, Then graph two periods of the function of: 1) y=3 sin(x-pie/4) 2) y=0.25cosx+3

**Physics**

A car enters the freeway with a speed of 5 . 6 m/s and accelerates uniformly for 3.6 km in 2.7 min. How fast is the car moving after this time? Answer in units of m / s

**chemistryhelp**

how many moles of excess reactant are present when 3.20 x 10^2 mL of 0.226 M sulfuric acid reacts with 0.531 L of 0.185 M sodium hydroxide to form water and aqueous sodium sulfate

**Math - Advanced Functions**

the function f(x)=-0.005x^2+0.8x+12 models the relationship between a certain vehicle's speed and a fuel economy, where f(x) is the fuel economy in kilometres per litre and x is the speed of the vehicle in kilometres per hour. Determine the rate of change in fuel economy ...

**math**

30

**Logarithm**

The rate of auto thefts triples every 6 months. (a) Determine, to two decimal places, the base b for an exponential model y = Ab^t of the rate of auto thefts as a function of time in months. b = (b) Find the doubling time to the nearest tenth of a month. months

**Physics**

Water flows into a swimming pool at the rate of 5 . 25 gal / min. If the pool dimensions are 33 . 8 ft wide, 40 ft long and 11 . 1 ft deep, how long does it take to fill the pool? (1 gallon = 231 cubic inches) Answer in units of min

**Calculus**

Thanks!!

**Calculus**

You have just opened a new nightclub, Russ' Techno Pitstop, but are unsure of how high to set the cover charge (entrance fee). One week you charged $9 per guest and averaged 165 guests per night. The next week you charged $10 per guest and averaged 150 guests per night. (a...

**math**

it would be the root of 837

**Math (Algebra)**

3 robots go out to lunch. They decide to share the $11.91 bill evenly. How much does each robot pay? Equation: 3x = 11.91 #1. What does x represent? #2. Solve for x. #3. Answer the question.

**Math (Algebra)**

The Problem is that 3 people go to lunch. They decide to share the $12 bill evenly. How much does each person pay? The Equation is 3x=12 #1. What is the value of x? #2. Solve for x #3. Answer the question.

**math**

If a prism was filled with 43 cubes with half unit side lengths. what is the volume of the prism in cubic units?

**social studies**

what religion did India's mughal conquerors follow

**statistics**

In a carnival game, a player spins a wheel that stops with the pointer on one (and only one) of three colors. The likelihood of the pointer landing on each color is as follows: 65 percent BLUE, 22 percent RED, and 13 percent GREEN. Note: Your answers should be rounded to three...

**Physics**

A 4 kg crate slides down a ramp.the ramp 2.9 m in length and incline at an angle of 35 degress.the crate start from rest at the top and has a friction force of 3 n.what is the speed of the crate

**Math**

The difference between the prices of two bikes is $22. The sum of the prices is $328. How much does each bike cost?

**math**

Order the numbers from least to greatest 4/6,4/8,3/4,5/8

**Chemistry**

How do I find the number of particles in 1 pound of NH3(Ammonia)?

**Chemistry :) simple question**

gas hydrogen is released qand it comes from the bubbles as t forms when acid is added to a metal

**physics**

An ethernet cable is 3.95 m long and has a mass of 0.190 kg. A transverse pulse is produced by plucking one end of the taut cable. The pulse makes four trips down and back along the cable in 0.820 s. What is the tension in the cable?

**Algerbra**

HELP!!!!!!! I have to find a rule for the following in and out. Input: 1,2,3,4 Output: 3,9,18,30 Thank you!!

**AP Physics**

Thanks!

**AP Physics**

So my question is about projectile motion. We just learned in class about the equation for finding the range: R=v^2sin(2theta)/g I understand that and I think I see where it comes from. My question is, if someone were to collect data on the projectile range for different ...

**History**

The 10th amendment basically says that any powers that the Constitution doesn't give to the federal government or keep the states from having automatically are reserved for the States. One example would be that since constitution doesn't give the federal government ...