# Posts by Emily

Total # Posts: 2,963

**Physics**

A sports car accelerates from rest to 89 km/h in 6.1s . What is its average acceleration in

*October 21, 2010*

**Physics**

If you are driving 100km/h along a straight road and you look to the side for 1.9s , how far do you travel during this inattentive period?

*October 21, 2010*

**physics**

If you are driving 100 along a straight road and you look to the side for 1.9 , how far do you travel during this inattentive period?

*October 21, 2010*

**Math**

Determine the domain and range of f(x)=-sqrt(x+3) and the equation of the inverse.

*October 21, 2010*

**Math**

If f(x)=x^2-6x+14 and g(x)=-x^2-20x-k, determine the value of k so that there is exactly one point of intersection between the two parabolas.

*October 21, 2010*

**Biology**

What does the net movement of solutes/solvents during osmosis and diffusion mean?

*October 20, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...

*October 20, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...

*October 20, 2010*

**physics**

find the frictional force between an air hockey puck and the table, assume u air = 1.8 X 10^-5 kg/ms, the puck is 0.013 above the table, the puck has an area of 25 cm^2

*October 19, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...

*October 19, 2010*

**chemistry**

A coal burning plant that burns 4 metric tons of coal containing 2% sulfur (S) requires 1 metric ton of wet limestone (calcium carbonate) to remove 90% of the sulfur. The process prevents most of the sulfur from being emitted as sulfur dioxide to the air by producing calcium ...

*October 19, 2010*

**precalc**

find where f(x)<0 and f(x)>0 f(x)=xlnx-2x

*October 18, 2010*

**Math**

Given f(x)=7-2(x-1)^2, x>= 1, determine f inverse (5).

*October 18, 2010*

**Math**

Given f(x)=2x^2-1, determine the equation of the inverse.

*October 18, 2010*

**Math**

Given f(x)=7-2(x-1)^2, x>= 1, determine f inverse (5).

*October 18, 2010*

**Chemistry**

what is the wavelength of the photon emitted when an electron drops from a 4p orbital to a 2p orbital in a hydrogen atom

*October 18, 2010*

**Biology**

A cell has a salt concentration of 0.2 %. If it is placed into a solution with a salt concentration of 0.1 %. a) What change will occur to the salt concentration inside the cell? b)What change will occur to the water concentration inside the cell? c)What condition will ...

*October 18, 2010*

**Economics**

True or false: The US must remove tariffs and quotas to open trade with foreign countries. Consider the following issues: The definition of tariffs and quotas. The strength of the dollar on domestic and global economies. Benefits from tariffs or quotas, including examples. ...

*October 18, 2010*

**Chemistry**

Given a 2.5 kg solution of phosphoric acid and water (56 % phophoric acid, by mass), calculate the number of moles of phosphoric acid.

*October 18, 2010*

**Chem**

I got 100125 is that correct?

*October 17, 2010*

**Chem**

The specific heat capacity of aluminum is .89 J/y degrees C. How much heat is required to change the temp of 1500g aluminum pan from 25 degrees C to 100 degrees C?

*October 17, 2010*

**Chem**

The specific heat capacity of aluminum is .89 J/y degrees C. How much heat is required to change the temp of 1500g aluminum pan from 25 degrees C to 100 degrees C?

*October 17, 2010*

**calculus**

Find the equation of a cubic function that gives you the surface area of the cans given a set volume. The set volume is 300ml

*October 17, 2010*

**Photography**

What's the difference between the setting of the enlarger height and focusing the image? Aren't both of the dealing with the light that shines onto the baseboard?

*October 17, 2010*

**Math**

What does it mean by: Show that the "value of 3x^2-6x+5" cannot be less than 1. ?

*October 15, 2010*

**Physics**

Oh! thanks! I understand it now :D

*October 15, 2010*

**Physics**

So it's 20 x 0.8=16?

*October 15, 2010*

**Physics**

A certain force made a 5.0 kg mass accelerate at 4.0 m/s^2. This same force made another object accelerate at only 0.8 m/s^2. Find the mass of the second object. I have no idea how to do this. Do i use m=1/a? What do i do?

*October 15, 2010*

**Physics- Newton's 1st and 2nd Law**

Thank you so much for the help!!

*October 14, 2010*

**Physics- Newton's 1st and 2nd Law**

Please help me :( Briefly explain the following scenario's using Newton's first law. a) Trevor wants to tow Kevin's car with his truck. He attached a small tow rope between the vehicles and leaves the rope slack (loose). Trevor quickly accelerates forwards making ...

*October 14, 2010*

**Math**

This was my monday home work i had to attempt it brcause we are learning that tomorrow and I got it yay

*October 13, 2010*

**Math**

3/4*177/236 you get that by dividing 4 and 236 you get 59. Or cross multiply. 3*236=4x, 708 = 4x ,177x

*October 13, 2010*

**Math**

What are the vertical and horizontal stretch/compressions for the functions h(x)=1/(5x) and k(x)=|0.4x| ?

*October 11, 2010*

**physics**

A car drives straight off the edge of a cliff that is 56 m high. The police at the scene of the accident note that the point of impact is 129 m from the base of the cliff. How fast was the car traveling when it went over the cliff?

*October 11, 2010*

**Physics**

I understand the mass should be divided by the density for the required volume. I don't think that I am using the correct numbers. I came up with a volume of 172800 or 1.7 x 10^5 but the answer is incorrect. Can you please help?!! I did (1000V)(10)(500) = 1.7x 10^5

*October 11, 2010*

**Physics**

where would I use the 9.8m/s^2? And the density is which number?

*October 11, 2010*

**Physics**

To store the energy produced in 1.5 hour by a 160 MW (160 10^6 W) electric-power plant, how many cubic meters of water will have to be pumped from the lower to the upper reservoir? Assume the upper reservoir is 500 m above the lower and we can neglect the small change in ...

*October 11, 2010*

**Math**

A 5 m stepladder propped against a classroom wall forms an angle of 30 degree with the wall. Exactly how far is the top of the ladder from the floor? Express your answer in radical form. What assumption did you make?

*October 10, 2010*

**math**

find a function y=ax^2+bx+c whose graph has an x-intercept of 1, a y-intercept of -2, and a tangent line with slope -1 at the y-intercept.

*October 9, 2010*

**Math**

Given any right triangle with an acute angle theta, a) Explain why csc theta is always greater than or equal to 1 b) Explain why cos theta is always less than or equal to 1

*October 8, 2010*

**hist**

who were the pilgrims and what did they believe?

*October 8, 2010*

**algebra**

A brick border that is x feet wide is built around a rectangular patio. The patio is 6 feet wide and 8 feet long. The combined area of the patio and the brick border is 120 square feet. What is the width of the brick border?

*October 7, 2010*

**algebra**

If the area of a square is 9x2-12xy+4y2, what is the perimeter of the square in terms of x and y. *its 9x squared and 4y squared i have several problems like this on my homework if you show me how to do this one im sure i could figure out the rest

*October 6, 2010*

**algebra**

Elliot is 5 times as old as Sid. Ten years from now, Elliot will be at least 3 times as old as Sid will be then. At least how old is each person now?

*October 6, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. You are 133 m from the intersection when you begin to apply ...

*October 6, 2010*

**Physics**

i do not think that is correct because i am getting the incorrect answer.

*October 6, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. You are 133 m from the intersection when you begin to apply ...

*October 6, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. You are 133 m from the intersection when you begin to apply ...

*October 6, 2010*

**Physics**

A speedboat starts from rest and accelerates at +2.07 m/s2 for 7.00 s. At the end of this time, the boat continues for an additional 6.00 s with an acceleration of +0.523 m/s2. Following this, the boat accelerates at -1.55 m/s2 for 8.00 s. What is the velocity of the boat at t...

*October 6, 2010*

**Physics**

nope :(

*October 5, 2010*

**Physics**

kk got that. did you get number 18?

*October 5, 2010*

**Physics**

okay ! and which q'n did u get 255 m for?

*October 5, 2010*

**Physics**

k i got this one.. find the t it takes for each runner using t=d/v....then subtract the times, and you have the answer !

*October 5, 2010*

**Physics**

A speedboat starts from rest and accelerates at +2.07 m/s2 for 7.00 s. At the end of this time, the boat continues for an additional 6.00 s with an acceleration of +0.523 m/s2. Following this, the boat accelerates at -1.55 m/s2 for 8.00 s. What is the velocity of the boat at t...

*October 5, 2010*

**Physics**

You are driving to the grocery store at 14.8 m/s. You are 140.0 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.440 s and that your car brakes with constant acceleration. How far are you from the intersection when you begin to apply...

*October 5, 2010*

**Physics**

alrighttyy. did u get number 13, 14 or 18?

*October 5, 2010*

**Physics**

okay thanks ! was your velocity really small and negative then?

*October 5, 2010*

**Physics**

okay but what does 'u' refer to? Also, for question #7, how did you figure out the total velocity for the entire trip?

*October 5, 2010*

**Physics**

oh okay i got that ! thanks. for the second part..how long it takes to reach the bottom.. do u use t = d/v?

*October 5, 2010*

**Physics**

yes. but how did you get it because i have different numbers

*October 5, 2010*

**Physics**

I have this same question.. got it wrong

*October 5, 2010*

**Science**

thks

*October 5, 2010*

**Science**

What is a experimental investigation? What is a descriptive investigation?

*October 5, 2010*

**Physics**

Superwoman is hovering above the ground when a person free-falling goes by her at a terminal velocity of 140 km/h. Unfortunately, the parachute does not open. Fortunately, Superwoman is around. If it takes her 1.9 s to realize the person is in distress, what must her ...

*October 3, 2010*

**Biology**

How does a plant growth regulator differ from a plant growth hormone?

*October 3, 2010*

**AP world history**

i have to write a DBQ promt question for the interaction between humans and the enviornment (demography and disease, migration,technology, and patterns of settlement) about roman empire

*October 3, 2010*

**Physics**

Two rugby players are running towards each other. They are 37 m apart. If one is accelerating from rest at 0.5 m/s^2 and the other was already moving at 3.1 m/s and maintains her speed, a)how long before they crunch together? b)How fast was the accelerating player going? c)How...

*October 2, 2010*

**Physics**

A police car stopped at a set of lights has a speeder pass it at 100 km/h. If the police car can accelerate at 3.6 m/s^2, how long does it take to catch the speeder?

*October 2, 2010*

**7th grade**

5x-10-2x+7=0 3x-3=0 3x=3 x=1

*October 1, 2010*

**Physics**

Thanks!

*October 1, 2010*

**Physics**

On a velocity-time graph of a person's walk, if a person is slowing down in the positive direction, then acceleration is in the negative direction.For example, the positive direction is [E]. If a person's acceleration is -1m/s^2, then it is 1 m/s^2 [West]. But that ...

*October 1, 2010*

**Math**

How did u get the answer?

*October 1, 2010*

**Math**

Ali did his homework at school with a graphing calculator. He determined that the equation of the line of best fit for some data was y=2.63x-1.29. Once he got home, he realized he had mixed up the independent and dependent variables. Write the correct equation for the relation...

*October 1, 2010*

**Math**

If f(x)=x^2, what is the domain and range of y=0.5f(3(x-4))-1?

*September 30, 2010*

**Physics**

Thanks!

*September 30, 2010*

**Physics**

If 100 m sprinters accelerate from rest for 3.5 s at 2.8 m/s^2, how far have they run to this point? How long will it take them to complete the 100 m sprint, assuming they maintain their speed the rest of the way? I found the distance, which is 17 m, and the distance they ...

*September 30, 2010*

**Economics**

Name 2 government bodies or agencies that have an impact on the national housing market. Explain the role of each body or agency in relation to the housing market.

*September 29, 2010*

**physics**

I don't understand this part.... 2) force*distance=1/2 m v^2 force= mass*(4g)/2d= 2*g*mass/.74

*September 29, 2010*

**chem 101**

yay i was right, thank you very much for your help

*September 29, 2010*

**chem 101**

a.write a balanced chemical equation for the complete combustion of sucrose. --- this part of the question i got help on, and thank you b. if combustion is complete, a brown liquid caramel might form, followed by a brown/black solid. what would be the major component of the ...

*September 29, 2010*

**chem 101**

if combustion is complete, a brown liquid caramel might form, followed by a brown/black solid. what would be the major component of the solid?

*September 29, 2010*

**chem 101**

write a balanced chemical equation for the complete combustion of sucrose.

*September 29, 2010*

**Economics**

How can you use information about the business cycle when making a decision about a large purchase?

*September 28, 2010*

**math**

explain why 1734 is greater then 175

*September 27, 2010*

**italian**

How do i say my name in italian.

*September 27, 2010*

**arithmetic**

Thanks 68%

*September 23, 2010*

**arithmetic**

Thanks

*September 23, 2010*

**arithmetic**

I got 102 questions right out of 150 on a math test. What percentage did I get on theis test?

*September 23, 2010*

**chemistry**

1.70

*September 22, 2010*

**geography**

Rivers bring water for ______ and ____. ?????? Fill in the blank with no options.

*September 21, 2010*

**Geography**

What is the second longest river in North America?

*September 21, 2010*

**physics**

A rock climber throws a small first aid kit to another climber who is higher up the mountain. The initial velocity of the kit is 21 m/s at an angle of 58° above the horizontal. At the instant when the kit is caught, it is traveling horizontally, so its vertical speed is ...

*September 20, 2010*

**Physics**

Dini is riding her bike eastward at a constant 9.5 m/s when a car pulls out of a side street a short distance in front of her. Dini applies her brakes and manages to stop in 2.5 s, just in time to avoid running into the car. Calculate Dini's average acceleration. The ...

*September 20, 2010*

**12th grade maths**

How do you express x^2-49? (x+7)(x-7) X(times)X = X^2 (positive 7) (times) (negative 7)= -49 X^2-49 is (x+7)(x-7).

*September 20, 2010*

**Physics**

Sandy is racing her sister home, but they each take a different route. Who will win: the one with the greatest average speed or the one with the greatest average velocity? Explain, using some sample numbers.

*September 19, 2010*

**Biology**

In which of the following environments would you be most likely to find non-vascular plants: in desert soil, near the snow line on a mountain, on a sandy ocean beach, or on the forest floor? Give reasons for your answer.

*September 19, 2010*

**Physics**

It's in my science textbook.

*September 18, 2010*

**Physics**

a)Why is it more important for an aircraft pilot to know the wind velocity than the wind speed? b)Why is it more important for all pilots to use the same conventions when describing velocity?

*September 18, 2010*