Posts by mayra

Total # Posts: 45

Science
a beaker has 130 ml of water in it. a rock is placed in the beaker and the water level rises to 148ml. what is the volume of the rock?

math
so do I

Chemistry
The volume of a gas is increased from 100mL to 250 mL by heating it.If the original temperture of the gas was 15.0°c what will be the final temperture in °c

Chemistry
A 25.0-g sample of sodium hydroxide is dissolved in 400.mL of water. What is the concentration of the solution?

Chemistry
Consider a 500mL solution containing 2.0×10^-5 mol HCl ·what is the pH of the above solution? ·If the solution is diluted to 1.5 L what will be the new pH?

Chemistry
A compound has an empirical formula of CH2 and molecular mass of 84g. What is it's molecular formula?

Chemistry
How many moles of a gas are present in 2.0L cylinder at 1.50 atmospheres and 17 degree's celcius?

Math
Potatoes are sold in 2.25 pound bags. How many whole bags must Tanisha buy in order to have enough potatoes

math
questions 3 :- Mrs. Scott decided that she would spend no more than \$120 to buy a jacket and a shirt.

Math
The area of a rectangular hallway is 120 square feet. If the length and the width are both composite numbers what are the possible dimensions of the hallway? Would it be 40 by 4?

English
Thank you

English
Which ones are right so I have an idea what to go on

English
Are the pronouns I put down right? My answers are the ones in parentheses 1. The trip led to an argument between Helen and _____. (I) 2. It was ____ who demanded an apology from the newspaper. (us) 3. We appreciated ____ writing a personal letter to explain his stand on the ...

curriculum content
when are children first developmentally ready to begin learnig science?

algebra
one inch is about 2.254 centimeters .A puzzle has a length of 28 centimeters .What is the length of the puzzle in inches ,rounded to the nearest tenth of an inch

geometry
A triangle has side lengths of 6, 8, and 9. What type of triangle is it?

Are you sure that it is H3C?

math
First Convert the inches the mowed width made so that would be 24in x 1ft/12in so you would get 2 feet. So then you would have to divide how wide the yard is by the mowed width. So 50/2 would five you 25. Hope this helps and was what you asked.

Physics
A car owner forgets to turn off the headlights of his car while it is parked in his garage. If the 12.0-V battery in his car is rated at 150.0 A · h and each headlight requires 41.4 W of power, how long will it take the battery to completely discharge?

Algebra
Try to do everything inside each individual parenthesis. So in this case I see that there are a lot of fractions, try to convert everything into fractions and that will make the math inside the parenthesis much easier. Once you have them all you can go ahead and multiply them ...

math
on a map the scale is 1/2 inch=25 miles for each map distance.. so 3 inch= 8 3/4 inch=

Pre- Calc
power is -3/5 and constant is 4

Pre- Calc
Determine if the fuction is a power function. If it is, then state the power and constant of variation. f(x)=4x^(-3/5)

Math
2 1/3

statistics
Why does the standard of error of a mean decrease as population increases.

Math
24

math
1 & 2

math
how do you Construct a 90% confidence interval for the population average time to complete the tax forms.

math
Suppose that an accounting firm does a study to determine the time needed to complete one person's tax forms. It randomly surveys 100 people. The sample average is 23.8 hours. There is a known population standard deviation of 6.0 hours. The population distribution is ...

s <= 25

English
I want complete one paragraph about write one paragraph of eight to twelve sentences persuading a friend to enroll in Penn Foster by describing at least three advantages of distance-education with Penn Foster compared to a traditional school education. Use the comparison-...

chemistry
actually drake was right on his first answer i had this question on my homework and it is d. less than a few years :)

physics
If the ball is in equilibrium when the string makes a 25.9◦ angle with the vertical as indicated, what is the net charge on the ball? Answer in units of µC.

physics
a 5.1 kg bucket water is raised from a well by a rope. the acceleration of gravity is 9.81 m/s^2. if the upward acceleration of the bucket is 4.5m/s^2, find the force exerted by the rope on the bucket of water.

MATH!
63 mph

math
idk

biology
does the cell theory state that cell come from cells that already exist?

biology
does the cell theory state that cell come from cells that already exist?

algebra
my question is this how do you solve this equation? x=3y-1 x+2y=9 solve each system of equation by the substitution method.

Math
How can I "prove" that a negative times a negative is a positive.

Science
How did mendel's approach to answering scientific questions differ from that of his contemporaries?

mental math
|y|=9

mento math
|y|=9 9 -9

algebra a/b
|y|=9

Arrays
What do you call numbers that cannot be arranged into 2-row arrays? Those would be the odd numbers or numbers without a factor of 2 in them.