# Posts by Erika

Total # Posts: 459

**physical science **

If sam drops a 40 kg mass from a height of 20 meters on earth how much was the potential energy of the mass before he dropped it a-800 j b-784 n-m c-800 n-m d-7840 j e- 200 j

*March 14, 2017*

**physical science **

a 500 kg elevator is lifted 10. How much work was done a 50 j b 50 j /kg c 5000 j d 5000 j/kg degree c

*March 14, 2017*

**help**

physical science may you help me

*March 14, 2017*

**help**

science

*March 14, 2017*

**help **

work is measured in which of the following units a n b n-m c m d kg m/sec /sec

*March 14, 2017*

**help**

you right

*March 14, 2017*

**help**

this is science

*March 14, 2017*

**help **

if fred took a 40 N weight and dropped it from 10 meters. what would be the potential energy before he released it a 400j b 40 n-m c 392 n-m d 3920 j e 4000 j

*March 14, 2017*

**science**

so would the answer be B

*March 14, 2017*

**science **

If sam drops a 40 kg mass from a height of 20 meters on earth how much was the potential energy of the mass before he dropped it a-800 j b-784 n-m c-800 n-m d-7840 j e- 200 j

*March 14, 2017*

**english**

Help!!!!! What does the Quote "In winter I plot and plan, In spring I move" mean.

*March 12, 2017*

**Chemistry**

T/F The absorption lines of neon occur at slightly different wavelengths than its emission lines. My answer: I thought that they would have the exactly opposite wavelengths? Am I missing something?

*March 5, 2017*

**Astronomy**

T/F The absorption lines of neon occur at slightly different wavelengths than its emission lines.

*March 5, 2017*

**Math**

please if anyone could help me with this question: 1. A class paid $20 for a cake and $4 per child for one slice of cheese pizza. they paid $140. how many children are in the class? 2. Rajie want to divide 24 peanuts, 64 raisins, and 56 apricots evenly into packets (with 0 ...

*February 23, 2017*

**math**

PLEASE TELL ME THE ANSWER TO "blank 569 divided by 6 is about 400!!!!!!!!" WHAT IS THE BLANK?!!?!?!?

*February 23, 2017*

**Math**

Know if 28 and 3 if the first number is multiple of the second

*February 14, 2017*

**Science**

The mutual gravitational attraction between two masses in space is 686 Newtons. What is the new gravitational force between these masses if the distance between them is increased by a factor of 5.6? To be graded correctly, enter the new weight in Newtons (numbers only, no text...

*February 6, 2017*

**Science**

Physics A scientific instrument weighing 98 pounds on the Earth is transported to another planet whose mass is 1.7 Earth masses and whose radius is 0.7 Earth radii. What does this instrument weigh on this planet? To be graded correctly, enter the new weight in pounds (numbers ...

*February 6, 2017*

**chem**

Using the equation 2H2 + O2 ==> 2H2O, determine how many grams of water is produced when 29 moles of oxygen is consumed

*January 24, 2017*

**chem**

Using the equation 2H2 + O2 ==> 2H2O, determine how many grams of water is produced when 29 moles of oxygen is consumed

*January 24, 2017*

**US History**

Thanks for trying

*January 19, 2017*

**US History**

4) Which of the following did not account for the development of the cattle industry in the 1870s & 1880s? a) growth of a transportation network. b) the ability to raise large herds on smaller plots of land. c) Overgrazing resulted in larger higher sale price cattle. d) Low ...

*January 19, 2017*

**math**

damon borrowed $1000 for 1 year and 7 months at an interest rate 6.3% compounded monthly. how much did he repay

*December 21, 2016*

**Calculus**

Sinx=e^y , 0 <x <pi, what is dy/dx in terms of x?

*December 5, 2016*

**Calculus**

For what value of k will x+k/x have a relative max at x=-2

*December 5, 2016*

**Algebra**

I think D

*November 28, 2016*

**Algebra**

What are the equivalent fraction and decimal for 33 1/3%? A. 1/33 and 0.3 B. 1/33 and 3 C. 3 1/3 and 0.333333 D. 1/33 and 0.333333

*November 28, 2016*

**Math**

If you can measure the length and width of a rectangle correct within .1cm then the calculateday area will be correct .1cm as well. Is this true or false?

*November 18, 2016*

**Calc**

Evaluate the following integral using a geometric formula Integral of -2 to 6: |x-1|dx

*November 18, 2016*

**Calculus**

Use the second fundamental theorem of calculus to find F'(x) F(x)=The integral from 0 -> x^2 (Sin(x)^2)dx

*November 18, 2016*

**Calculus**

Find the average value of the function over [1,3] and all values of x in the interval for which the function: f(x)= 4(x^2+1)/x^2 equals its average value.

*November 16, 2016*

**Maths**

Let r'(t) represent the rate of growth of a dog in pounds per year. What does r(t) represent? What does integral of 2 to 6 r'(t) represent about the dog?

*November 16, 2016*

**math geometry**

Please help so hard. My problem... In the coordinate plane point C lies on line segment AB. The coordinates for MN are (2,4) and (16,12). If the ratio of the length of AC to the length of CB is 3:4, what is the x-coordinate of point C?

*November 8, 2016*

**chemistry**

Write a balanced equation for the double-replacement precipitation reaction described, using the smallest possible integer coefficients. A precipitate forms when aqueous solutions of iron(II) iodide and sodium hydroxide are combined.

*November 4, 2016*

**chemistry -3.2.4**

Given the reaction: Cu2+(aq) + S2-(aq) CuS(s) What will happen (a) if CuSO4(aq) is added? And (b) if Na2SO4(aq) is added? A. (a) Nothing; (b) Less product will form B. (a) Less product will form; (b) Nothing C. (a) Nothing; (b) More product will form D. (a) More product will ...

*September 15, 2016*

**chemistry - 3.1.6**

At a high temperature, the equilibrium constant for the decomposition of hydrogen iodide is 65.0. If the initial concentration of HI is 1.60 M, what is the concentration of hydrogen at equilibrium? 2Hl(g) H2(g) + I2(g) A. 1.42 M B. 0.753 M C. 0.240 M D. 0.802 M I'm ...

*September 15, 2016*

**chemistry - 4.1.4**

The [OH-] ion concentration of a sample is 1 × 10-10 M. What is the concentration of [H+] in the sample at 25°C? A. 1 × 10-14 M B. 1 × 10-4 M C. 1 × 10-10 M D. 1 × 10-6 M I think the answer is C. is this correct?

*September 15, 2016*

**chemistry**

The titration of HCl with NaOH is an example of: A. a strong acid-weak base titration. B. a weak acid-weak base titration. C. a weak acid-strong base titration. D. a strong acid-strong base titration. I know that this is a strong acid but not sure about the base? what do you ...

*September 15, 2016*

**chemistry**

What is a neutralization reaction? A. A reaction that involves neutral reactants B. A reaction in which the reactants are a salt and water C. A reaction in which the product is either acidic or basic D. A reaction that removes essentially all H+ and OH- I know that it isn'...

*September 15, 2016*

**chemistry**

I think that the answer to this one is A, as i know that the concentration of the reactants is high. I'm not sure about whether its products or reactants as the numerator though?

*September 15, 2016*

**chemistry**

If the equilibrium constant is much less than 1, what can you conclude about the concentrations of the reactants and products? A. Reactants are in the numerator of the equilibrium expression, so the concentration of the reactants is high. B. Products are in the numerator of ...

*September 15, 2016*

**chemistry**

How can you shift the equilibrium of the reaction between hydrogen and chlorine toward the products? H2(g) + Cl2(g) --> 2HCl(g) A. Add Cl2. B. Remove H2. C. Increase the pressure. D. Add HCl. would the answer to this one be to add Cl2? so answer A?

*September 15, 2016*

**chemistry**

not sure. can you show me how to work through it?

*September 15, 2016*

**chemistry**

Given the reaction: Cu2+(aq) + S2-(aq) CuS(s) What will happen (a) if CuSO4(aq) is added? And (b) if Na2SO4(aq) is added? A. (a) Nothing; (b) Less product will form B. (a) Less product will form; (b) Nothing C. (a) Nothing; (b) More product will form D. (a) More product will ...

*September 15, 2016*

**chemistry**

the answer was B? K<Q

*September 15, 2016*

**chemistry**

The equilibrium constant for the formation of phosphorus pentachloride is 1.9. If the partial pressure of each gas is 0.5 atm, will the reaction (as written) proceed forward or backward to reach equilibrium? PCl3(g) + Cl2(g) PCl5(g) A. Backward, because K is greater than Q B. ...

*September 15, 2016*

**chemistry**

What effect does raising the temperature of the reaction chamber at a constant pressure have on the following reaction at equilibrium? 2NO2(g) N2O4(g) + heat A. The equilibrium shifts toward the reactants because the reverse reaction is endothermic. B. The concentration of NO2...

*September 15, 2016*

**chemistry**

Why does the density of gas in a hot air balloon decrease as the gas is heated? A. The mass of gas decreases as temperature increases. B. The mass of gas increases as temperature increases. C. The volume of gas decreases as temperature increases. D. The volume of gas increases...

*September 14, 2016*

**AP Chemistry**

sorry for commenting on a q that isn't mine but my calculator doesn't let me find the value for 10^-7. do you know why? and also what the value is?

*September 14, 2016*

**chemistry**

What is the chemical equation that describes the complete neutralization of H3PO4 by NaOH? A. H3PO4 + 2NaOH Na2HPO4 + 2H2O B. H3PO4 + H2O H2PO4- + H3O+ C. H3PO4 + NaOH NaH2PO4 + H2O D. H3PO4 + 3NaOH Na3PO4 + 3H2O

*September 14, 2016*

**chemistry**

Which of the following is true about the results of a neutralization reaction? A. An acid and a base form water and salt. B. Water reacts with a base to form the hydroxide ion. C. Water reacts with an acid to form the hydronium ion. D. An acid and a base dissociate into their ...

*September 14, 2016*

**chemistry**

Knowing what information would allow you to order gas molecules according to their velocity? A. Pressure and temperature B. Volume and molecular mass C. Pressure and volume D. Temperature and molecular mass

*September 14, 2016*

**chemistry**

How does table salt (NaCl) dissolve in water? A. Water molecules hydrogen bond with sodium ions and chloride ions. B. Each sodium ion is surrounded by chloride ions. C. Each NaCl molecule is surrounded by water molecules. D. The oxygen atoms in water molecules attract sodium ...

*September 14, 2016*

**geometry**

The perimeter of triangle ABC is 13 cm. It was dilated to create triangle A'B'C' The perimeter of triangle...is cm

*August 31, 2016*

**Biology**

What is your answer?

*August 30, 2016*

**medical insurance**

the patient is seen by his family physician for follow-up treatment of recently diagnosed asthmatic bronchitis. the physician's fee is 75$. the patient copayment is 20$, and the patient is not required to pay any additional amount to provider. the payer reimburses the ...

*July 14, 2016*

**math help please**

The distance a spring stretches varies directly with the force applied to it. If a 7-pound weight stretches a spring a distance of 24.5 inches, how far will the spring stretch if a 12-pound weight is applied?

*January 12, 2016*

**math help please**

A jewelry store uses a markup rate of 70% on all items. If the wholesale price of a pair of earrings is $15.00, what is the retail price for the earrings?

*January 12, 2016*

**math help please**

Morgan had a bag of jolly ranchers. She counted 8 watermelon flavored candies in the bag of 46. If she bought a super-size bag with 138 jolly ranchers, how many could Morgan expect to be watermelon flavored?

*January 12, 2016*

**math help please**

Chumley from the TV show "Pawn Stars" bought some vintage watches for $15 each. He sold five of the watches for $36 each. What was the total amount of profit made for the watches sold?

*January 12, 2016*

**math help please**

On the blueprint of a portable stage is 1 cm = 10 m. The length of the stage on the blueprint is 2 cm and the width is 1/2 cm. What is the perimeter of the actual portable stage?

*January 12, 2016*

**math help please**

The graph gives a breakdown of the hours students use the tutoring center. If the graph is based on 300 students, how many used the center 8 to 10 hours during the week? 1-3 h 27% 3-5 h 22% 5-8 h 26% 8-10 h 15% over 10 h 10%

*January 12, 2016*

**math help please**

Miranda baked 48 muffins to sell at the school bake sale. She sold 2/3 of the muffins and gave the rest to her friends to eat. How many muffins did she sell?

*January 12, 2016*

**math help**

Claire earns a 15% commission from her lipstick sales. Her sales for the month of April were $400. How much commission did Claire earn for her April sales?

*January 12, 2016*

**math help**

On the blueprint of a portable stage is 1 cm = 10 m. The length of the stage on the blueprint is 2 cm and the width is 1/2 cm. What is the perimeter of the actual portable stage?

*January 12, 2016*

**math help**

The temperature at 1:00 pm on Tuesday was -13C. There was an increase of -6 per hour starting at 1:00 pm. Which of the following best represents the Celsius temperature n hours after 1:00 pm on Tuesday?

*January 12, 2016*

**math help**

Tia's parents gave her $20 to spend at the Spring Carnival. She spent $5 on a funnel cake and the remaining money on tickets for rides. If each ride ticket costs $0.75, how many ride tickets did she purchase?

*January 12, 2016*

**math help**

Jimmy spends ¾ of an hour getting ready for school. It takes 30 minutes to travel to school. If he needs to be at school at 9:00 am, what time should he get up?

*January 12, 2016*

**math help**

Hank rode his motorcycle half the distance from Lumberton to Wilmington, which are 70 miles apart. How many miles did he ride?

*January 12, 2016*

**math**

It is 3 miles around Westwood Park exercise trail. After skating around the trail 5½ times, Mr. Zorn lost a wheel. How many miles had he skated? Round your answer to the nearest mile.

*January 12, 2016*

**math**

Donald bought 10 woodcarvings for a total of $220. If they were all the same price, how much did he pay for each wood carving?

*January 12, 2016*

**math 1**

An advertiser needs a 4-inch picture of a 14 foot automobile. What is the scale factor? Write your answer in simplest form using a colon.

*January 11, 2016*

**math 1**

Sarah calculated the points she earned on her test. Sarah thought she earned 95 points but the teacher told her she actually only scored 85 points. What was Sarah's percent error. Round to the nearest tenth.

*January 11, 2016*

**math**

target is advertising a Sony camcorder for $299.99 this week. If the regular price is $329.99, what is the percent of discount customers are receiving for this item? Round your answer to the nearest whole number.

*January 11, 2016*

**math**

3.6 is 12% of what number?

*January 11, 2016*

**math**

A jewelry store purchases earrings from a manufacturer for $5.00 each. If the store wants to mark up the price by 75%, what will be the retail price of the earrings?

*January 11, 2016*

**chemistry**

How many formula units are in 1.31 mg of hydrogen peroxide (H2O2)? Answer in units of formula units. For 508 g of butadiene (C4H6) calculate the number of moles. Answer in units of mol. Calculate the number of molecules. Answer in units of molec. 016 1.0

*January 10, 2016*

**chemistry**

How many molecules are in 24.0 g NO2? Answer in units of molec.

*January 10, 2016*

**chemistry**

How many molecules are in 0.0700 mol NH3? Answer in units of molec.

*January 10, 2016*

**chemistry**

How many molecules are contained in 1.30 mol O2? Answer in units of molec.

*January 10, 2016*

**chemistry**

How many grams do 6.2×1024 atoms of argon weigh? Answer in units of g.

*January 10, 2016*

**Math And Science for Young Children**

No, A

*January 9, 2016*

**Chemistry**

A pot containing 500 g of water at 100 degrees Celsius would require how much energy to boil off completely

*December 7, 2015*

**math 7th**

a candle was 45 cm long .It was lit and 20% burned off .The candle went out.The next day it was lit again ,and 25% of the remaining candle burned out .then it went out On the third day the candle was lit 1/3 of the remaining amount burned off .then it went out .how long was ...

*December 1, 2015*

**math 7th**

the cost (c) is twice of the cost of a 7$ tape what is the price of the cd

*December 1, 2015*

**math**

Juan sold a boat that he bought 5 years ago. He sold it for 70%less than he originally paid for it. If the original cost is b , write an expression that shows how much he sold the boat for

*November 18, 2015*

**math**

Ms.Sue i need your help please

*November 18, 2015*

**math**

pine city (x) is less than or equal to 20 miles from sun vally depending on the route you take how many miles is pine city from sun vally

*November 18, 2015*

**math**

Ms .sue i think s is for march sales

*November 18, 2015*

**math**

this month`s sales of $85,000 are greater than 1/2 of the sales of march repesented by the letter . What was March`s sales .

*November 18, 2015*

**Chemistry**

How do you find the Ka1 and Ka2 of oxalic acid when it is in a solution that is 1.05 M H2C2O4 and has a pH of 0.67. [C2O4^2-] = 5.3x10^-5 M. I have tried using an ICE table for both reactions, as oxalic acid is a diprotic acid, but I am having trouble knowing where to put ...

*November 1, 2015*

**Physics**

A student standing on the ground throws a ball straight up. The ball leaves the student's hand with a speed of 17.0 m/s when the hand is 1.50 m above the ground. How long is the ball in the air before it hits the ground? (The student moves her hand out of the way.)

*September 17, 2015*

**Algebra**

I'm trying to find the sum of this geometric series but I can't find a common ratio. How do I find it? 1+1/5+1/25+...

*September 8, 2015*

**Algebra**

I'm trying to find the sum of this geometric series but I can't find a common ratio. How do I find it? 1+1/5+1/25+...

*September 8, 2015*

**Algebra**

I've been try to solve this equation and I can't seem to get far. Do you add 3 to both sides? If not please explain to me how you solve this. Thanks :) 1/2=2/5c-3

*September 1, 2015*

**organic chemistry**

isobutyl tert pentyl acetylene has how many hyrogen atoms? iso=2 butyl=4 tert=4 pentyl=5 acetylene=2 28 h atoms? can you please teach me how to compute hydrogen atoms.. Neoheptane has how many atoms?

*July 11, 2015*

**organic chemistry**

evaluate the number of carbon for the ffg. pairs by writing G if greater, L if less than or E if equal 1. butene E sym dimethylethylene sol'n: butene has 4 carbons and sym dimethylethylene also has 4 carbons so it's equal. Am i right? 2. methylbutane L isopentane ...

*July 11, 2015*

**algebra**

morgan saw 10 blue cars 8 red cars and 42 white cars drive by her house in 1 hour what is the experimental probability that the next car will not be white

*March 12, 2015*

**math**

maria throws a ball straight up with an initial velocity of 10m/s what is its velocity at the highest point?

*March 10, 2015*

**Math**

Pick any single digit number. Multipy it by 12,345,679. Then multiply the result by 9. What happens? Explain why this works.

*March 1, 2015*