Saturday

May 23, 2015

May 23, 2015

Total # Posts: 2,958

**chemistry**

dissolved oxygen in aquatic systems is important for the survival of freshwater fish and they require a minimum of 5 parts per million(ppm) of dissolved oxygen (02) in a stream lake to survive. although this amount seems small, how many oxygen molecules are in a litre of water...
*January 6, 2015*

**Science**

A mass extinction is a catastrophic event because _______?
*January 6, 2015*

**Math**

In a triathlon, a contestant swims 5 km, cycles 30 km, and then runs 20 km. In general, a contestant runs at an average speed of x, swimsat an average speed of x/5, and cycles at an average speed of 5x, where x is in kilometres per hour. a) Determine an expression for the ...
*January 6, 2015*

**Math**

The velocity of an object is given by the formula v=25t-80, where the time is expressed in seconds and the velocity is expressed in feet per second. Find the times when the magnitude of the velocity is equal to 60 ft/s
*January 6, 2015*

**Math**

The area of a tennis court can be represented approximately by the function A(x) = 10x2 + 3x - 1, and its length can be represented by l(x) = 5x - 1, where x is a distance, in metres. a) Write and simplify a function, w(x), to represent the width of a tennis court. (2 marks) b...
*January 6, 2015*

**Math**

A scientist is monitoring the temperature of a holding tank containing fish to be released into a river. In one 12-h period, the highest temperature was 10.4°C and the lowest temperature was 7.6°C. Write an absolute value equation that can be used to report the highest...
*January 6, 2015*

**physics**

The movement of an object or a point mass at a constant speed around a circle that has a fixed radius is called uniform
*December 18, 2014*

**Math**

Simplify each expression and state any non-permissible values. (4 marks - show your work) 4x-1 divided by x^2+7x+12 divided by 2x-1 divided by x^2 +x- 12 is the expression Help me please and thank you.
*December 18, 2014*

**Math**

Simplify each expression and state any non-permissible values. (4 marks - show your work) x^2-2x divided by x+1 multiplied by x^2-1 divided by x^2+x-6 is the expression
*December 18, 2014*

**This site is the best. Thanks a lot :)**

Thanks a lot for everything. Have a great Holidays :)
*December 16, 2014*

**Math**

A museum calculates the rate for groups using the equationC=4P+8,where P is the number of people and C is the total cost in dollars. If the cost for a group is $60, how many people are in the group?
*December 15, 2014*

**algebra**

1) log sub 8 2 + log sub 8 4x^2 = 1 2) ln 2 - ln (3x + 2) = 1 3) ln (x - 3) - ln (x - 5) = ln 5
*December 11, 2014*

**Math**

Courtney and Kurtis are planning to travel 160 km in a car by travelling at x kilometres per hour for the first half of the distance, and then increasing their speed by 10 km/h to finish the distance. Which is the correct simplified expression for the total time of the trip? a...
*December 10, 2014*

**Math**

The non-permissible values for the expression -9x+8 divided by -9x^2-55x+56 are? a) x does not equal -8/9 b)x does not equal 8 c) x does not equal 8/9 and x does not equal -7 d) there are no restrictions
*December 10, 2014*

**Math**

Express the product, x^2 + 4x divided by 2x^2+13x+15 multiplied by x+5 divided by x^2 - 16 ? a)-1/2x+3 b)x/(2x-16)(x+4) c)(x^2+4x)(x+5) / (2x^2+13x+15)(x^2-16) d)x / (2x+3)(x-4)
*December 9, 2014*

**Math**

When fully simplified, ignoring non-permissible values, 12x^12/4x^3 divided by x^8/24x^6? a)72x^3 b)1/72x^7 c)1/72x^3 d)72x^7
*December 9, 2014*

**Math**

How would I simplify this quadratic equation: y=-15/20.25(x^2+3x+2.25)+0 This is my work already done the original equation I was given but I need help simplifying the equation I have found.
*December 8, 2014*

**Math**

When fully simplified, ignoring non-permissible values, 12x^12/4x^3 divided by x^8/24x^6? a)72x^3 b)1/72x^7 c)1/72x^3 d)72x^7
*December 8, 2014*

**Math**

When fully simplified, ignoring non-permissible values, 12x^12/4x^3 divided by x^8/24x^6? a)72x^3 b)1/72x^7 c)1/72x^3 d)72x^7
*December 5, 2014*

**Math**

When fully simplified, ignoring non-permissible values,24x^18/6x^3 x x^8/30x^6? a)15/2x^8 b)2/15x^8 c)15/2x^17 d)2/15x^17
*December 5, 2014*

**physics**

A blue puck has a velocity of 3i –4j m/s. Its mass is 20 kg. What is its momentum?
*December 4, 2014*

**Math**

Express the product x^2+4x/2x^2+13x+15 x x+5/x^2-16 in simplest form. a)- 1/2x+3 b)x/(2x-16)(x+4) c)(x^2+4x)(x+5)/(2x^2+13x+15)(x^2-16) d)x/(2x-3)(x-4)
*December 4, 2014*

**Math**

I have got help from Damon on this question but all I need is help on integrating the answer he gave me into my original equation: y=-15/20.25(x+1.5)^2+0 Here's Damon's help: (x+1.5)(x+1.5) = x^2 + 1.5 x + 1.5 x + (1.5*1.5) = x^2 + 3 x + 2.25 So how would I put this ...
*December 4, 2014*

**Math**

have got help from Damon on this question but all I need is help on integrating the answer he gave me into my original equation: y=-15/20.25(x+1.5)^2+0 Here's Damon's help: (x+1.5)(x+1.5) = x^2 + 1.5 x + 1.5 x + (1.5*1.5) = x^2 + 3 x + 2.25 So would I put this into my ...
*December 4, 2014*

**Math**

a=?,P=5,00,r=2.75,t=10 A=P(1+rt) A=5,000(1+2.75*10) A=5,000(1+27.5) A=5,000(28.5) A=142,500
*December 4, 2014*

**Math**

I have got help from Damon on this question but all I need is help on integrating the answer he gave me into my original equation: y=-15/20.25(x+1.5)^2+0 Here's Damon's help: (x+1.5)(x+1.5) = x^2 + 1.5 x + 1.5 x + (1.5*1.5) = x^2 + 3 x + 2.25 So would I put this into ...
*December 4, 2014*

**Math**

So then how would I put it into the original equation, Damon?
*December 4, 2014*

**Math**

My math teacher said to use the FOIL (First Outer Inner Last) property to simplify these quadratic equations I have made from looking at two parabolas. Here are my equations & how would you use the FOIL property on each of the equations and also can someone help me with ...
*December 4, 2014*

**Math**

How would I simplify these two equations I have made up from looking at parabolas: y=-15/20.25(x+1.5)^2+0 y=a(x+2)^2+1.5
*December 4, 2014*

**Science**

a ball with a mass of 1.50 kg traveling + 2.00 m/s collides with a stationary ball with a mass of 1.00 kg. After the collision, the velocity of the 1.50 kg ball is + 0.40 m/s. What is the velocity of the 1.00 kg ball after the collision?
*December 4, 2014*

**Chemistry**

In the carbon diselenide, CSe2, identify the number of σ and π bonds, the necessary hybridization scheme and the orbital overlap. Thanks
*December 3, 2014*

**physics**

a glider with a mass of 5 kg is moving to the right on a horizontal frictionless surface at 6 m/s when it collides with a 8 kg glider that is at rest. After the collision, the 8kg glider is moving to the right at 6 m/s. what are the speed and direction of the 5 kg glider ?
*December 3, 2014*

**chemistry**

There are no known stable cyclic compounds with a ring size of seven or less that has an alkyne linkage in the ring. Why?
*December 3, 2014*

**Math**

I am 2 digit number The difference between them is less then 1 The sum of them is a multiple of 9 The second digit is a factor of 27 What number am I ?
*December 2, 2014*

**Chemistry**

A student dissolves 22.4 g of sodium phosphate to prepare a 2.98 L solution. Another student then dilutes this solution to 4.90 L. If sodium phosphate completely dissociates, determine the number of mols of each ion in the final solution.
*December 1, 2014*

**Physics**

A puck (uniform disk) of mass m and radius r is travelingat a speed v on frictionless ice. It strikes a second identical puck a glancing blow (at point P) and sticks to it (using VelcroTM). After the collision, the two-puck-object rotates with angular velocity ω about its...
*November 30, 2014*

**Physics**

A child of mass m is playing on a merry-go-round which has mass 6m and radius r. Assume the merry-go-round is a uniform disk. The child is standing on the edge of the merry-go-round, which is spinning with an angular speed ω1. a) What is the moment of inertia, I1, of the ...
*November 30, 2014*

**Physics**

A 500.0 g bird is flying horizontally at 2.25 m/s, not paying much attention, when it suddenly flies into a stationary vertical bar, hitting it two-thirds of the way up from the bottom. The bar is uniform and very thin, is 0.750 m long, has a mass of 1.50 kg, and is hinged at ...
*November 29, 2014*

**Math**

How would I expand this two quadratic equations and find a & x for both of them? Here are my equations: y=a(x+1.5)^2+0 y=a(x+2)^2+1.5
*November 28, 2014*

**Math**

The illumination of an object by a light source is directly proportional to the strength of the source and inversely proportional to the square of the distance from the source. If two light sources, one four times as strong as the other, are placed 11 ft apart, how far away ...
*November 28, 2014*

**Math**

A ball is thrown straight up from a bridge over a river and falls into the water. The height, h, in meters, of the ball above the water t seconds after being thrown is approximately modeled by the relation h=-5t^2+10t+35. Can you please help me ! Show your work. a) What is the...
*November 26, 2014*

**Physics**

A two dimensional object placed in the xy plane has three forces acting on it: a force of 3N along the x axis acting at a point (3m, 4m); A force of 2N along the y axis acting at (-2, 5m); and a force of 5N in the negative x direction acting at (-2m, -3m). What is the net ...
*November 23, 2014*

**Math**

What is the vertex of y=7(x+5)^2+4?
*November 21, 2014*

**physics**

A particle of mass and initial velocity strikes a stationary particle of mass . The collision is elastic. It is observed that after the collision the particles have equal and opposite velocities: Find (a) the ratio ; (b) the velocity of the CM (before and after the collision...
*November 21, 2014*

**Math**

I also need the other intercept. How would go about figuring it out? Please and thank you, Steve.
*November 20, 2014*

**Math**

What are the x-intercepts of y=(x-6)(y-9)?
*November 20, 2014*

**Math**

Which function is not quadratic? a)f(x)=x(x-3)(-6x+5) b)f(x)=-6(x-2)^2 c)f(x)=-3x^2+5 d)f(x)=(-6x+3)(1/2x-3)
*November 20, 2014*

**Physics help please**

A 0.504 m length of conducting wire carrying a current of 62.1 A is?
*November 19, 2014*

**physics **

A lightning strike transfers 25.1 C of charge in (6.49x10^-3) s. The current during this lightning strike is _.__x10^ A?
*November 19, 2014*

**physics**

If a person pushes on a block and it travels a distance of 6.0m before stopping. How far would the block travel if it were pushed with the same force, but on the moon(which has 1/6 of the earth's gravity).
*November 19, 2014*

**Math**

7/15 divided by 3/10 =
*November 19, 2014*

**Chemistry**

Assume you are performing the calibration step of Experiment 8 and you begin with 20 g of water at 20 oC and 20 g of water at 80 oC. After adding the two portions of water into your calorimeter setup and following the procedure outlined in the experiment, you determine the ...
*November 17, 2014*

**Chemistry**

if 5.00 ml of 1.66x10^-1 M HCl solution is diluted to exactly 250.0 ml with water, what is the concentration of the resulting solution?
*November 16, 2014*

**calc**

Sorry +5
*November 13, 2014*

**calc**

verify that g(x)=3x sqrt(x-5) satisfies the condition of rolle's theorem on the interval [0,5]. Find all numbers c that satisfies rolles theorem.
*November 13, 2014*

**Molecular Calculations**

if you had 118.7 gm of Sn; how many grams of oxygen would need to convert al the Sn into SnO^2
*November 13, 2014*

**Math**

Mike's age, decreased by the age of his 4 year old sister is 11. Mikes age, increased by his uncle's age is 53. How old is Mike's uncle?
*November 12, 2014*

**Physics**

A plate falls vertically to the floor and breaks up into three pieces, which slide along the floor. Immediately after the impact, a 200g piece moves along the x-axis with a speed of 2.00m/s and a 235g piece moves along the the y axis with a speed of 1.50m/s. The third piece ...
*November 12, 2014*

**Physics**

A plate falls vertically to the floor and breaks up into three pieces, which slide along the floor. Immediately after the impact, a 200g piece moves along the x-axis with a speed of 2.00m/s and a 235g piece moves along the the y axis with a speed of 1.50m/s. The third piece ...
*November 9, 2014*

**Physics**

A simple pendulum of length 2.00m is made with a mass of 2.00kg. The mass has speed of 3.00 m/s when the pendulum is 30 degrees above its lowest position. -What is the maximum angle away from the lowest position the pendulum will reach? -What is the speed of the mass when the ...
*November 9, 2014*

**Derivatives**

Can you help me find the derivative of this function, I keep messing up of the steps :( f(x)= (x-2)(x^2-3x-1)
*November 9, 2014*

**physical science**

Sophia exerts a steady 40-N horizontal force on a 8-kg box resting on a lab bench. The box slides against a horizontal friction force of 24 N. Show that the box accelerates at 2 m/s2.
*November 9, 2014*

**Math Please help**

I do not have any Idea how to set this up. Please walk me through the steps. A.) If a customer buys x copies then he or she pays $500 sqrt x. it cost the company $10,000 to develop the program and $2 to manufacture each copy. If a single customer were to buy all the copies of ...
*November 6, 2014*

**Physics**

An Escort and a Camaro traveling at right angles collide and stick together. The Escort has a mass of 1200 kg and a speed of 25 km/h in the positive x direction before the collision. The Camaro has a mass of 1700 kg and was traveling in the positive y direction. After the ...
*November 6, 2014*

**Physics**

A ball of mass 0.60 kg is fired with velocity 100 m/s into the barrel of a spring gun of mass 2.4 kg initially at rest on a frictionless surface. The ball sticks in the barrel at the point of maximum compression of the spring. No energy is lost to friction. What fraction of ...
*November 6, 2014*

**Physics**

A simple pendulum of length 2.00m is made with a mass of 2.00kg. The mass has speed of 3.00 m/s when the pendulum is 30 degrees above its lowest position. -What is the maximum angle away from the lowest position the pendulum will reach? -What is the speed of the mass when the ...
*November 5, 2014*

**Math**

Consider the function y = –2(x – 12)^2 + 18. a) What is the axis of symmetry of the graph of the function.(1 mark)
*November 5, 2014*

**math**

(-4/5)-6=-14
*November 4, 2014*

**physics**

A 1100- kg car collides with a 1500- kg car that was initially at rest at the origin of an x-y coordinate system. After the collision, the lighter car moves at 20.0 km/h in a direction of 35 o with respect to the positive x axis. The heavier car moves at 23 km/h at -50 o with ...
*November 4, 2014*

**Physics**

A ball of mass 0.60 kg is fired with velocity 100 m/s into the barrel of a spring gun of mass 2.4 kg initially at rest on a frictionless surface. The ball sticks in the barrel at the point of maximum compression of the spring. No energy is lost to friction. What fraction of ...
*November 4, 2014*

**Physics**

A 1100- kg car collides with a 1500- kg car that was initially at rest at the origin of an x-y coordinate system. After the collision, the lighter car moves at 20.0 km/h in a direction of 35 o with respect to the positive x axis. The heavier car moves at 23 km/h at -50 o with ...
*November 4, 2014*

**Math**

Explain why (2,-3) would be the vertex of the function y=-3(x-2)^2-3? Please and thank you!
*November 4, 2014*

**Physics**

A ball of mass 0.60 kg is fired with velocity 100 m/s into the barrel of a spring gun of mass 2.4 kg initially at rest on a frictionless surface. The ball sticks in the barrel at the point of maximum compression of the spring. No energy is lost to friction. What fraction of ...
*November 4, 2014*

**Physics**

A 0.145- kg baseball with an initial speed of 27 m/s rebounds with a speed of 32 m/s after being struck with a bat. If the duration of contact between ball and bat was 1.5 ms, what was the magnitude of the average force between ball and bat?
*November 4, 2014*

**Math**

Water spraying from a large fountain follows a path modeled by the function h(d) = -2/3d^2+ 4d, for h > 0, where h is the height of the water above the fountain jet and d is the horizontal distance of the water from the fountain jet, both in metres. a) Graph the function (...
*November 3, 2014*

**Math**

I can't remember how you find the roots of quadratic equations other than determining the zeroes of the equation and finding the x-intercepts. Can someone please give me a clear answer on this as my dad has been useless on this topic and I need help like ASAP! You can find...
*November 3, 2014*

**Math**

Water spraying from a large fountain follows a path modelled by the function h(d) = sa001-1.jpgd2 + 4d, for h ³ 0, where h is the height of the water above the fountain jet and d is the horizontal distance of the water from the fountain jet, both in Water spraying from a ...
*November 3, 2014*

**Math**

I can't seem remember the rules for this.Can someone please help me with the following questions? You can find the roots of a quadratic equation by determining the zeros of the quadratic function or the ...? You can find the roots of a quadratic equation by determining the...
*November 3, 2014*

**Math**

(x+4)(x-9)=0 I need help because I have tried all the answers as this a multiple choice question. a) (x+4)(x-9) (4+4)(-9-9) (8)(-18) -144 b) (x+4)(x-9) (4+4)(9-9) (8)(0) 0 c) (x+4)(x-9) (-4+4)(9-9) (-8)(0) 0 d) (x+4)(x-9) (-4+4)(-9-9) (0)(-18) 0
*November 3, 2014*

**Math**

Where did you get the 1 + 2 square root 2 for the answer? Please explain more thoroughly for the answer and how you got it.
*November 3, 2014*

**Math**

A ball is thrown straight up from a bridge over a river and falls into the water. The height, h, in meters, of the ball above the water t seconds after being thrown is approximately modeled by the relation h=-5t^2+10t+35. c) After how many seconds does the ball hit the water?
*November 3, 2014*

**Calculus**

Using an appropriate linear approximation approximate 26.9^(4/3).
*October 31, 2014*

**Solving inequalities **

I've had so much trouble so much trouble with this if somebody could help me I would be so grateful g + 3 > 6
*October 31, 2014*

**Math**

Solve the quadratic function y=2x^2-14x -16 by completing the square. Round roots to the nearest hundredth, if necessary. Show your work.
*October 30, 2014*

**stats**

A company wishes to make 1 ounce candy bars. According to government regulations, in order to label the candy bars as 1 ounce, at least 95 % of the bars must weigh 1 ounce or more. Our process standard deviation is .08 ounces. What do we need to make the mean weight be so that...
*October 29, 2014*

**Math**

Solve (x+4)(x-9)=0
*October 29, 2014*

**Math**

A projectile is shot vertically into the air. Its height, h, in metres, after t seconds is approximately modelled by the relation h=-5t^2+120t+125: c) For how many seconds is the projectile in the air? (1 mark)
*October 29, 2014*

**Calculus**

New York state income tax is based on taxable income which is part of a person's total income. The tax owed to the state is calculated using taxable income (not total income). In 2005, for a single person with a taxable income between $20,000 and $100,000, the tax owed ...
*October 29, 2014*

**Math**

The value of k that makes the expression x^2 + 72x +k a perfect square trinomial is ?
*October 28, 2014*

**math please help**

Custom Kitchens received an invoice dated November 17 from Idea Cabinets Ltd. for $7260 with terms 3/15, 15/30,n/60. If Custom Kitchens made a payment of $4000 on December 2, what further payment on December 16 will settle the account?
*October 27, 2014*

**Math invoice**

Custom Kitchens received an invoice dated November 17 from Idea Cabinets Ltd. for $7260 with terms 3/15, 15/30,n/60. If Custom Kitchens made a payment of $4000 on December 2, what further payment on December 16 will settle the account?
*October 27, 2014*

**Math**

Custom Kitchens received an invoice dated November 17 from Idea Cabinets Ltd. for $7260 with terms 3/15, 15/30,n/60. If Custom Kitchens made a payment of $4000 on December 2, what further payment on December 16 will settle the account?
*October 27, 2014*

**Physics **

A block of mass m1 = 41.3 kg on a horizontal surface is connected to a mass m2 = 13.2 kg that hangs vertically as shown in the figure below. The two blocks are connected by a string of negligible mass passing over a frictionless pulley. Assume that the horizontal surface is ...
*October 27, 2014*

**Science**

Carbon monoxide, CO, and hydrogen, H2, react according to the reaction below. 4 CO(g)+ 9 H2(g)--> C4H10(g)+ 4 H2O(g) What volume of the excess reactant remains if 19.6 L CO and 27.2 L H2 are allowed to react. Assume that the volumes of both gases are measured at 713oC and 1...
*October 22, 2014*

**Chemistry**

What is the pressure (in mmHg) of the gas inside the apparatus below if the atmospheric pressure is Patm=748 mmHg, h1=40 mmHg, and h2=67 mmHg?
*October 22, 2014*

**Math**

State whether the function y=-2x^2-8x+17 has a maximum or minimum value and identify the coordinates of the vertex.
*October 22, 2014*

**Chemistry**

A 35.0-L cylinder contains 387 g O2(g) at 22.5°C. What mass of O2(g) must be released to reduce the pressure in the cylinder to 5.94 atm, assuming the temperature remains constant?
*October 21, 2014*

**Chemistry**

What is the pressure (in mmHg) of the gas inside the apparatus below if the atmospheric pressure is Patm=748 mmHg, h1=40 mmHg, and h2=67 mmHg?
*October 21, 2014*

**Physics**

a boat moves through the water of a river at 5.8m/s relative to the water, regardless the boat's direction. if the current is flowing at 5.04m/s, how long does it take the boat it take the boat to complete a trip consisting of a 443m displacement downstream followed by a ...
*October 20, 2014*

**Physics**

The answer was 22.2m...
*October 20, 2014*