# Posts by Melissa

Total # Posts: 1,309

**physics**

A woman pushes a refrigerator across the floor at a steady speed of 20cm/s . If she has to push with a horizontal force of 400 N to keep it moving , is the force of friction less than 400 N , 400 N, more than 400 N, why

**physics**

Thank you so much, i understand a lot more now !

**physics**

A jet plane is traveling at a constant speed in a straight line in level speed. What does this tell you about the forces acting on it, what forces are acting on it .

**physics**

thank you bobpursley

**physics**

A triathlete swims 1200 m due to east followed by 1500 m due northeast (45o). What is the overall displacement? (magnitude and angle). Calculate the displacement with long-hand calculations.

**physics**

Thanks bobpursely I need this for my Quantitative Biomechanics class

**physics**

A diver is jumping straight up with 2 m/s from a 15 meter platform. Calculate the maximum height of the diver, the diver’s velocity when reaches the water, and total time to reach the water.

**Calculus**

A rectangular prism is defined by vectors (2,0,0) (0,9,6) and (0,0,3). Find the volume.

**Geometry**

The height of the segment from the apex of the cone to the base is 10 feet. The length of the diameter of the circular base is 4 feet. Calculate the volume

**Geometry**

The height of the segment from the apex of the pyramid to the base is 10 feet. The length of the diagonal of the square base is 4 feet. Calculate the volume

**geometry**

a ladder is 53 inches. how tall is it in feet and inches

**Calculus and vectors**

I don't know, I think that it is A-B=C

**Calculus and vectors**

Explain how the vector C⃗(Going from the head of B⃗ to the head of A⃗) can be written in terms of vectors A⃗ and B⃗ Given the shape in this url: imgur dot com/5nT3V

**Calculus and vectors**

Please, help I don't understand vectors T.T 1. In the prism, assume all dimensions have different lengths, state the following: a) state 3 equal vectors to DC⃗ b) state 4 opposite vectors to BC⃗ ------------------------------------- Here is the prism below, ...

**art history**

How would you compare and contrast the northern and southern style temple?

**Physics**

A athlete in good physical condition can land on the ground at a speed of 12m/s without injury , calculate the max height from which the athlete can jump without injury, assuming the takeoff speed is zero

**Physics**

A student throws a baseball vertically upward, and 2.8s later catches it at the same level. Neglecting air resistance , calculate the following (a) the velocity at which the ball left the students hand (b) the height to which the ball climbed above the students hand

**math**

B

**Physics**

A car is doing a loop-the-loop. The loop has a radius of .4m. Assume the car is starting with the minimum speed it needs in order to stay in contact with the track at all times (at the top of the track, the car is not applying a force to the track). neglect friction. What is ...

**geometry**

60ft

**geometry**

120 ft

**college algebra**

A triangle is bounded by the x-and y-axes and must pass through P(2,2) a.) find the area of the triangle as a function of x (Hint: let C be the point (0,2) and D be the point (2,0). Use the fact that ACP and PDB are similar triangles.) b.) What is the domain of the function ...

**college algebra**

A piece of pottery is removed from a kiln and allowed to cool in a controlled environment. The temperature (in degrees Fahrenheit) of the pottery after it is removed from the kiln is shown for various times (in minutes) in the following table. Time(min) Temperature (F) 15 2200...

**college algebra**

A rectangle is bounded by the x-and y- axes and the graph of y = -1/2x + 4. a.) Find the area of the rectangle as a function of x. b.) Complete the following table x area 1 2 4 6 7 c.) What is the domain of this function?

**college algebra**

A magazine company had a profit of $98,000 per year when it had 32,000 subscribers. When it obtained 35,000 subscribers, it had a profit of $117,500. Assume that the profit P is a linear function of the number of subscribers s. a.) Find the function P b.) What will the profit ...

**college algebra**

Thank you and sorry someone impersonated you.

**college algebra**

sorry I will resubmit them. Thanks.

**college algebra**

yes

**physics**

If you were asked to design a capacitor in which small size and large capacitance were required, what factors would be important in your design?

**physics**

A river is moving at 4.0 m/s [s] , and a swimmer swims across it at 1.4 m/s [e] relative to the water. What is the swimmers velocity measure with respect to the river bank

**physics**

A river is moving at 4.0 m/s [s] , and a swimmer swims across it at 1.4 m/s [e] relative to the water. What is the swimmers velocity measure with respect to the river bank

**college algebra**

Given f(x)= 3x^2+x-30 and g(x)=x-3 find f(x)-g(x)

**college algebra**

Find the vertex for f(x)=-5x^2-6x=3

**economics**

An article in Business Week warned of the dangers of deflation as the collapse of numerous Asian economies was creating worries that Asia might try to “ export its way out of trouble” by oversupplying everything from automobiles to semiconductors. Evidence that ...

**Math**

A sensor light installed on the edge of a home can detect motion for a distance of 50ft. in front and with a range of motion of 192degree. Over what area will the sensor detect motion and become illuminated?

**math**

B=1.69 (sqrt (s)+4.45)-3.49 solve for s

**Math**

4t+14=6t/5+7

**Physics!! Help!!!!!**

A wire of length L and cross-sectional area A has resistance R. What will be the resistance R_stretched of the wire if it is stretched to twice its original length? Assume that the density and resistivity of the material do not change when the wire is stretched. Express your ...

**algrebra**

16(5/8x+1/16)x=16(7/16+x) I have no idea how to multiple 5/8 by 16

**chemistry**

who was the first scientist to identify a nuclear bombardment reaction?

**Physics!! Help!!!!!**

. A neutral conducting sphere contains a spherical cavity. A point charge +q is located at the |center of the cavity. A. What is the total surface charge on the interior surface of the conductor? B. What is the total charge on the exterior surface of the conductor?

**math**

the top will have a piece of marble 20 1/2 by 22 bordered by 3 1/4 inches of wood on all four sides. Give the overall dimension of the table top

**physics**

The angle between the polarizer transmission axis and the plane of polarization of the incoming light is 30 +/- 2 deg. If the incident light intensity Io is 100 W/cm2 what would be the intensity I after the light is transmitted through the polarizer? What would be the percent ...

**Precalculus**

Consider the equation 7sin^2x - (4sin2^x)/cosx = -1 a) Put the equation in standard quadratic trig equation form. Why is it 7sin^2x - 8sinx + 1 =0?

**Precalculus**

Which of the following is a solution for the equation 1/485tan^2x = 0? a) pi b) pi/2 c) 485pi d) no solution Which of the following is NOT a solution to the equation 4sin^2x = 1 for 0≤x≤2pi? a) 30 degrees b) 210 degrees c) 150 degrees d) 120 degrees?

**Precalculus**

Solve the equation (x+3)(x-3) = -9. What are the solutions to the equation if you replace x first with sinx and then with cosx, where 0≤x≤2pi?

**Precalculus**

Thank you!

**Precalculus**

Thank you~ May I know how you got 150 degrees? I am so confused when finding the reference angles, whether to subtract or add the degrees.

**Precalculus**

Sorry, I meant 2sinx - cos^2x = sin^2x for 0 ≤ x ≤ 2π 2sinx - cos^2x = sin^2x Do I change the left side to 2sinxcosx - cos^2x = sin^2x

**Precalculus**

Determine the solutions to the equation 2sinx − cos2x = sin2x for 0 ≤ x ≤ 2π . How do I start this question?

**Math**

How can I figure out what the line segment of radical, or Sq root of 17 looks like?

**Physic**

A cheetah can accelerate at a rate of 8.0 M/S^2. Assuming it starts from rest, what will its velocity be after 3.5 SECONDS?

**math**

a certain antibiotic redues the number of bacteria in your body by 10% each dse, if 4 doses of the antibiotic are taken, what percent of the original bacterial population is left

**math**

sam invested $5000 in a GIC earning 8% compound interest per year, the interest gets added to the amount invested, so the next year sam gets the interest on the interest already earned , as well as on te original amoun, how much will sam's investment be worth at the end of...

**math**

a student plants a seed, after the speed sprouts the student monitors the growth of the plant by measuring its height every week, the height after each of the first tree wees was 7mm , 20mm, and 33mm, respectively, if this pattern of growth continuesinwhat week will the plant ...

**math**

determine the 100th term of the arithmetic sequence with t7=465 and t13=219

**world religions**

In class I got this question any help would be great!! I have no clue how to answer it. If Jesus were human, what does this mean for Christianity and Judaism

**chemistry**

10 J

**science**

describe the path that oxygen follows through the human body to reach muscle tissue and describe the path carbon dioxide follows from inside the cell to the outside envrionment

**science**

what 3 anatomical factors influence a persons vo2max and what 3 internal physiological factors influence a persons vo2max

**math**

A catering company has 15 customer orders during its first month, for each month afterward, the comopany has double the number of orders than the previous month. How many orders in total did the company fill at the end of its first year ?

**math**

a ball is dropped from a height of 3m and bounces on the ground . At the top of each bounce, the ball eaches 60% of its previous height. Calculate the total distance travelled by the ball when it hits the ground for the fifth time

**Math**

The 13th termof an arithmetic sequence is 61 and the 20th term of the squence is 82. Calculate the sum of the first 25 terms of the sequence

**Math**

the 12th term in a geometric sequence is 49, and the 14th term is 2401 . Find the 15th term

**algebra**

The first 1/5 of a mile is $1.50. For every additional 1/5 of a mile is 25 cents. If Marc has $3.75, at least how far can he go? P.S. I need an inequality.

**physics 2B**

This ties in with chemistry actually. They give you Temperature, Pressure, and Volume. Convert temperature to Kelvins (add 273) and convert your volume to Liters. Use R constant 0.0821. Plug into the ideal gas law of PV=nRT and solve for the moles of the He atom (thats n). ...

**Chemistry**

Thanks so much! That makes alot more sense now. The figures really helped out.

**Chemistry**

Not to mention the conversions! But thanks a million. :) I got a range of an average of 0.064 nm to 0.45 nm. Considering concept wise though, do the units of nm make sense for an atoms diameter? That's not visible right?

**Chemistry**

True or False: The diameter of most atoms will be between 0.05 nm and 0.3 nm. I think its false (I don't think there even is an average diameter for atoms...), but I can't find any reliable sources to back up my hunch. Help please...

**math**

Matthew is riding a ferris wheel at a constant speed of 10km/h. The boarding height for the wheel is 1m, and the wheel has a radius of 7m. What is the equation for the function that describes Matthews height in the terms of time, assuming Matthew starts at the highest point on...

**Math**

The diameter of a car's tire is 60cm . While the car is being driven , the tire picks up a nail .How high above the ground is the nail after the car has travelled 1km

**Biology**

explain the process of adaptive radiation, and how are reproductive barriers important to speciation

**World religions**

For this project for school we have to represent the noble eightfold path ( right view) to canadian society , but i am so stuck , i don't really know anything that would make sense, any help would be great

**chemistry**

Calculate the pH of each of the following solutions. (a) 0.300 M propanoic acid (HC3H5O2, Ka = 1.3 10-5) (b) 0.300 M sodium propanoate (NaC3H5O2) (c) pure H2O (d) 0.300 M HC3H5O2 and 0.300 M NaC3H5O2

**chemistry**

The Ksp for silver sulfate (Ag2SO4) is 1.2 10-5. Calculate the solubility of silver sulfate in each of the following. A)water B)0.14 M AgNO3 C)0.33 M K2SO4 the answer in mol/L

**math**

how do u do lost digits?? my son has to do this for homework and we are both stuck on how to do this.

**Statistics**

The average hourly wage of employees in a large nationwide industry is $12.96. Assume the variable is normally distributed, with a standard deviation of $4.46. In a randomly selected sample of 10,000 such employees, how many of them (correct to the nearest hundred) would you ...

**statistics**

570 people were in a survey and 124 people said yes. What proportion of people said yes to 1 d.p

**chemistry**

Calculate the pH of a 0.063 M (C2H5)2NH solution (Kb = 1.3 10-3).

**Chemistry**

Calculate the molar heat of neutralization in kJ/mol of the reaction between HA and BOH given the following information: The temperature change equals 8C, 50 mL of 1 M concentration of Acid 50 mL of 1 M concentration of Base Heat capacity of the calorimeter is 6.5 J/C. ...

**math**

prove these identies sin^2+tan^2=sec^2-cos^2 sin^2 sec^2 +sin^2=tan^2+sin^2

**math**

An urn contains 5 red marbles, 4 blue marbles, and 3 green marbles. A marble is selected at random and then, without replacing the first marble, a second marble is selected at random. What is the probability of selecting a green marble and then a red marble?

**English**

What are the differences between the characters Johnny and dally, in the story The Outsiders by S.E. Hinton?

**english**

what does this mean? how can i summarize it ?? "we acquire language not just because we are taught it, but because we are born with the principles of language. They're in our genes. We have language because of nature, not just nurture"

**math**

Let R be a commutative ring in with a^2=a for every element a. Show that a+a=0 for all a in R

**MATH--PLEASE HELP**

Let W be the set of all continuous fuctions from the set of real numbers R to R. For f, g in W define f+g by (f+g)(x)=f(x)+g(x) and (f*g)=f(x)g(x). Verify that W is a commutative ring. Does W have unity? Why or why not?

**algebra**

7 * sqrt 20 = 7 * sqrt 5 * sqrt 4 = 7* sqrt5 * 2 = 14sqrt5 so (14sqrt5) - (8sqrt5)= 6sqrt5

**Physics**

Anyone know how to solve this problem?

**Biology**

In guinea pigs, gene B is for black, b is for white the heterozygote is a mixture, called agouti. ( sex linked and non dominant) , a litter consists of 5 agouti females and 6 black males , if the parents of this litter had more offspring , what other phenotypes would you ...

**Biology**

In man, muscular dustrophy , is inherited as a sex linked recessive , a couple , both of whom are normal, have five children, three boys and two girls , the oldest boy is beginning to show symptoms of the disease, what could you tell them about the chances of their children ...

**Biology**

Suppose that a clolur blind man has parents with normal vision. Would all his sons be colour-blind ? Was his mother a carrier ? would all his daughters be carriers

**math**

determine the value of k such that g(x)=3x+k intersects the quadratic function f(x)=2x^2-5x+3 at exactly one point determine the value(s) of k such that the linear function g(x)=4x+k does not intersect the parabola f(x)=-3x^2-x+4

**math**

Determine the equation of the inverese of the quadratic function f(x)=x^2-4x+3

**math**

The sum of two numbers is 16 . What is the largest possible product between these numbers

**math**

Express each function in standard form f(x)=-3(x-2)^2+5 f(x)=2(x+4)(x-6)

**math**

For a fixed element 'a' of a ring R, prove that the set {x exists in R such that ax=0)is a subring of R.

**History**

Did the Elastic Clause justify acts such as Hamilton's excise tax and the Bank of the United States or Jefferson's Louisiana Purchase?

**Math( help please ! )**

The profit p(x) of a cosmetics company , in thousands of dollars,is given by p(x)=-5x^2+400x-2550, where x is the amount spent on advertising , in thousands of dollars a) determine the max profit the company can make b)Determine the amount spent on advertising that will result...

**Math( help please ! )**

thank you so much

**Math( help please ! )**

The height of a ball thrown vertically upward from a rooftop is modelled by y=-5t^2+20t+50 , where h(t) is the ball's height above the ground , in meters , at time t seconds after the throw a) Determine the max height of the ball b) how long does it take for the ball to ...