# Posts by Alex

Total # Posts: 3,682

**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*

**Physics**

A 4.58 kg block located on a horizontal floor is pulled by a cord that exerts a force F = 10.5 N at an angle theta = 25.5° above the horizontal. The coefficient of kinetic friction between the block and the floor is 0.09. What distance does the block travel in a time of 5....

*October 20, 2014*

**Math**

Hi, I need help with figuring out how I calculated this question because my math teacher is asking "But my question is how do you get √2/2 How did you come up with that calculation?" Here's the question and my work for it: Chang is participating in a ...

*October 17, 2014*

**Math**

why would I have uarrived at square root 2 over 2 in this question Chang is participating in a charity bicycle road race. The route starts at Centreville and travels east for 13 km to Eastdale. He then makes a 135° turn and heads northwest for another 18 km, arriving at ...

*October 17, 2014*

**6th grade math**

a diver's elevation is -30 feet relative to sea level. she dives down 12 feet. what is her elevation after the dive? a. 12 feet b. 18 feet c. -30 feet d. -42 feet

*October 15, 2014*

**physics**

Consider three force vectors F1 with magnitude 42N and direction 140°, F2 with magnitude 27N and direction -110°, and F3 with magnitude 19N and direction 120°. All direction angles 0 (0 with a line inside) are measured from the positive x axis: counter-clockwise ...

*October 13, 2014*

**physics**

A person walks 27m east and then walks 31m at an angle 38° north of east. What is the magnitude of the total displacement. Answer in units of m

*October 13, 2014*

**physics**

A particle undergoes two displacements. The first has a magnitude of 135cm and makes an angle of 114° with the positive x axis. The resultant displacement had a magnitude of 183cm and is directed at an angle of 21.8° to the positive x axis. Find the magnitude of the ...

*October 13, 2014*

**physics**

A car travels 15.5 km due north and then 38.6 km in a direction φ = 74.3 ◦ west of north.Find the magnitude of the car’s resultant displacement. Answer in units of km

*October 13, 2014*

**physics**

A frictionless massless pulley has 7 kg tied to a cable on the left side and an unknown mass (M) on the right. The unknown mass accelerates downward at 6.6 m/s2 What is the accelerationof the system/tension of the rope

*October 13, 2014*

**polar co ordinates**

thanks so much ill have a look

*October 13, 2014*

**polar co ordinates**

how do you obtain the cartesian equation for r^2=16cos(3theata)?? I've tried looking on many website and at my notes but have had no luck. i know that r^2=x^2+y^2 and x=rcos(theta) but don't know were to go from here?

*October 13, 2014*

**Calculus**

derp

*October 12, 2014*

**physics**

suppose the force of 20.0 N pushes on two boxes of unknown mass. We know, however, that the acceleration of the boxes is 1.25 m/s2 and the contact force has a magnitude of 2.73 N. (a) Find the mass of box 1. (b) Find the mass of box 2. So do I subtract the contact force from ...

*October 11, 2014*

**physics**

In a tennis serve, a 0.070 kg ball can be accelerated from rest to 41 m/s over a distance of 0.90 m. Find the magnitude fo the average force exerted by the racket on the ball during the serve. I know it is a force problem, but I am not even sure how to set this up.

*October 11, 2014*

**Math**

What are the restrictions on x if the solution to the equation -4 - square root 4-x=6 involves real numbers?

*October 10, 2014*

**Physics**

The mass of a sports car is 1200 kg. The shape of the car is such that the aerodynamic drag coefficient is 0.250 and the frontal area is 2.30 m2. Neglecting all other sources of friction, calculate the initial acceleration of the car ,if it has been traveling at 85 km/h and is...

*October 9, 2014*

**Science**

no the answer is really B OK

*October 9, 2014*

**economics**

I need to address computer ability to grow the Gross domestic product ,create competition and make other industries efficient help me?

*October 9, 2014*

**math**

Mr. Winsett and Ms. Phelps are having a back to school party. Mr. winsett brought 48 hot wings and mrs. phelps brought 18 cans of soda. what is the greatest amount of people that can come and share the food equally with no left overs

*October 9, 2014*

**Physics**

A baseball is hit straight up in the air with an initial velocity of 26.7 m/s. How long in seconds does it stay in the air? (Hint: What is the overall distance of the ball?)

*October 8, 2014*

**Math**

f(x) = logx2

*October 8, 2014*

**Math**

A company manufactures fence sections for residential use. The number, s, of sections that can be produced per day is related to the number of hours, h, of labour required by the function s=2.1 square root h (Show your work) a) State the domain and range for the function. (2 ...

*October 8, 2014*

**algebra**

What is a quartic polynomial function in standard form with zeros 1, –2, –2, and –3?

*October 8, 2014*

**Chemical Engg**

Hello, where can i find the process flow diagram of a dyehouse? I searched on google, but in vain I really need a picture showing all the steps in the dyehouse plz!!

*October 8, 2014*

**Math**

A ball that is hit or thrown horizontally ball that is hit or thrown horizontally with a velocity of v metres per second will travel a distance d metres before hitting the ground, where d=v square root h/ 4.9 and h is the height, in metres, from which the ball is hit or thrown...

*October 7, 2014*

**math**

43.478%

*October 6, 2014*

**Physics**

A basketball is thrown at 45° to the horizontal. The hoop is located 6.2 m away horizontally at a height of 1.1 m above the point of release. What is the required initial speed? I know that I need to use d = vit + (0.5)at^2, but I then get stuck. Thanks!

*October 4, 2014*

**Algebra**

(3x^2-4x^3+7)+(-5x+11-7x^3-4x^2)

*October 2, 2014*

**Math**

What is the answer to 4 square root 1280 r^8 t^12 ?

*October 1, 2014*

**Chemistry**

How many grams of HCl are produced if the following reaction yielded 27.1 grams of H3PO4? PCl5 + 4 H2O --> H3PO4 + 5 HCl

*September 30, 2014*

**Math**

Solve the following e^-x (square root((3e^2x) - 5/4)) = e^x

*September 29, 2014*

**Algebra**

How do I simplify this problem. (2nr - nr^2)r - (2nr - nr^2) . 2r

*September 28, 2014*

**physics**

An electron in the cathode ray tube of a tele- vision set enters a region where it acceler- ates uniformly from a speed of 30100 m/s to a speed of 3.82 × 106 m/s in a distance of 2.97 cm. What is its acceleration? Answer in units of m/s2

*September 28, 2014*

**Algebra**

Adding and subtracting polynomials. Can someone help me solve this problem? 5x^3 . 2x^2 - 10x^4 + 3x^5 + 3x .(-2)x^4 . = The dot means to multiply. Thank you.

*September 28, 2014*

**physics**

An electron, starting from rest and moving with a constant acceleration, travels 5.8 cm in 14 ms. What is the magnitude of this acceleration? Answer in units of km/s2

*September 28, 2014*

**Algebra 1**

Adding and subtracting polynomials. (6-t-t^4) + (9t+t^4) How do you solve this problem?

*September 27, 2014*

**Math**

I already know the angle of Eastdale which is 45° due to the turn from due east to the northwest. So therefore so I need to find the measures of angle c and angle n. I can use the Law of Sines. sin‹C/c=sin‹E/e sin‹C/18=(√2/2)/12.7308 sin‹C=18(&#...

*September 26, 2014*

**English**

What rites of passage do individuals confront in the selection my brothers keeper?

*September 25, 2014*

**Math**

Why would you use square roots in the following question: Chang is participating in a charity bicycle road race. The route starts at Centreville and travels east for 13 km to Eastdale. He then makes a 135° turn and heads northwest for another 18 km, arriving at Northcote. ...

*September 25, 2014*

**Math**

State the side length of a square with an area of 27 cm2 in simplified radical form.

*September 25, 2014*

**Math**

What is ^4 square root 1280r^8 t^12 in simplified form?

*September 25, 2014*

**kindergarden Math**

sally has six flowers. three of the flower are yellow. the rest are red. how many are yellow?

*September 24, 2014*

**Math**

sally has six flowers. three of the flower are yellow. the rest are red. how many are yellow?

*September 24, 2014*

**Math**

sally has six flowers. three of the flower are yellow. the rest are red. how many are yellow? -kindergarden

*September 24, 2014*

**Math**

What is the vertex of y=7(x+5)^2+4?

*September 24, 2014*

**physics**

i need more information

*September 23, 2014*

**math**

The school cafeteria serves pizza every 6th day and applesauce every day Thursday supposed to pizza and applesauce are both on today's menu in how many days will they be together on the menu again?

*September 23, 2014*

**Chemistry**

Since a hydrogen atom consists of just one proton and one electron, it should have a mass of 1.673 x 10^-24 g. And so it does. Calculate how many hydrogen atoms you'd have if you had 5.6 g of hydrogen.

*September 23, 2014*

**Math**

The sine ratio is positive in the first and what other quadrant?

*September 23, 2014*

**Math**

Two wires are connected to a tower at the same point on the tower. Wire 1 makes an angle of 45° with the ground and wire 2 makes an angle of 60° with the ground. b) Which wire is longer? Explain. (2 marks) c) If the point where the two wires connect to the tower is 35 ...

*September 23, 2014*

**Math**

The expression cos 60° is equivalent to sin ?

*September 23, 2014*

**Analytical Chemistry (Titrations)**

Is molarity also called the concentration of the solution? I got 0.1641 M HCl. Thank you for your help!

*September 23, 2014*

**Analytical Chemistry (Titrations)**

I forgot: What is the concentration of the solution?

*September 23, 2014*

**Analytical Chemistry (Titrations)**

About 10ml of concentrated HCl was transferred to a 1-L volumetric flash and diluted to mark with distilled water. When this solution was used to titrate a sample of pure sodium carbonate, Na2Co3, weighing 0.3054 gram, it took 35.09 ml to reach the methyl red end point. The ...

*September 23, 2014*

**Math**

Which of the following triangles cannot be solved using the sine law? a) angle a= 28 degrees, angle b= 75 degrees, side a= 24 cm b) side a=4 cm , side b= 11 cm c) angle a=28 degrees, angle c= 34 degrees , side b=5 cm d) angle b= 29 degrees, side b=5 cm, side c=18 cm

*September 22, 2014*

**physics**

In order to qualify for the finals in a racing event, a race car must achieve an average speed of 276km/h on a track with a total length of 1520m. If a particular car covers the first half of the track at an average speed of 246km/h, what minimum average speed must it have in ...

*September 21, 2014*

**physics**

A speedy tortoise can run at 0.08 m/s, and a hare can run 16 times as fast. In a race, they start at the same time, but the hare stops to rest for 2 min, so the tortoise wins by a shells(20cm). How long does the race take? Answer in units of s

*September 21, 2014*

**Math**

Solve the following triangle, rounding side lengths to the nearest tenth of a unit and angle measures to the nearest degree. angle a = 153 degrees, b= 5, a=10.5

*September 21, 2014*

**Math**

Marco is 350 m due east of the centre of the park. His friend Ray is 350 m due south of the centre of the park. Which is the correct expression for the exact distance between the two boys?

*September 20, 2014*

**Math**

The first prize in a lottery is $250 000. Each winner chosen after the first is paid 20% as much as the winner before them. Determine a formula for the sum of n terms of the geometric sequence.

*September 19, 2014*

**Math**

For each arithmetic sequence, determine a) the value of t1 and d (2 marks) b) an explicit formula for the general term (2 marks) c) t20 (2 marks) 3a, 3a – 2b, 3a – 4b, 3a – 6b, …

*September 19, 2014*

**Algebra 2**

ok I get it. But what's the actual answer

*September 19, 2014*

**Algebra 2**

determine all symmetries of the function g(x)=x/x-1

*September 19, 2014*

**Algebra**

so you don't know

*September 19, 2014*

**Algebra**

Given a point (-2,5), determine a point that satisfies the specified symmetry. 1.)Origin 2.)y-axis 3.)x-axis 4.)y=x

*September 19, 2014*

**Math**

Find the value of term 1 given S8 is equal to -3280 and the common ratio is equal to -3?

*September 19, 2014*

**Math**

a) the value of t1 and d (2 marks) b) an explicit formula for the general term (2 marks) c) t20 (2 marks) 3a, 3a – 2b, 3a – 4b, 3a – 6b, …

*September 18, 2014*

**Math**

b) an explicit formula for the general term (2 marks) c) t20 (2 marks) 7/4, 1, 1-4, -1/2

*September 18, 2014*

**Math**

For each arithmetic sequence, determine a) the value of t1 and d (2 marks) b) an explicit formula for the general term (2 marks) c) t20 (2 marks) 7/4, 1, 1/4, -1/2

*September 18, 2014*

**Math**

Determine whether each sequence is geometric, arithmetic, or neither. Justify your answer. 1/5, 1/4, 1/3,1/2,1

*September 18, 2014*

**Math**

Find the value of term 1 given sum 8= - 3280a and the common ratio = - 3?

*September 18, 2014*

**Math**

A Registered Education Savings Plan (RESP) earns interest at a rate of 5% per year, compounded annually. Jasmine’s parents invest $4000 in the account today. a) Determine an explicit formula to represent the value of the investment. (2 marks) b) Use your formula to write ...

*September 18, 2014*

**Math**

The first prize in a lottery is $250 000. Each winner chosen after the first is paid 20% as much as the winner before them. b) Determine an explicit formula for the general term. (2 marks) c) Determine a formula for the sum of n terms of the geometric sequence. (2 marks) d) If...

*September 18, 2014*

**Math**

If S1 = 0.7 and S2 = 2.1 in a geometric series, determine the sum of the first 12 terms in the series. Be sure to show all of your work.

*September 17, 2014*

**Math**

The sum of the first two terms of an arithmetic series is 15 and the sum of the next two terms is 43. What are the first four terms of the series?

*September 17, 2014*

**Math**

Etienne owns a small recycling company that picks up empty glass bottles from restaurants. At the first restaurant, he picks up 50 bottles. At each restaurant after this, he picks up 4 more bottles than he picked up at the restaurant before. Assume that this pattern continues...

*September 17, 2014*