# Posts by emily

Total # Posts: 3,003

**math**

You want to cover a trapezoidal box with paper. You have a sheet of paper that is 1m by 500cm. What is the size box that can be made with minimal wastage? plz plz plz help me with this.. i don't understand how to do this

**Algebra**

You want to cover a trapezoidal box with paper. You have a sheet of paper that is 1m by 500cm. What is the size box that can be made with minimal wastage?

**Maths**

the total answer will be 437 +248 6 8 5

**Maths**

437 +248 do the math...

**Maths**

okay, and does the 4 at the bottom go under 3 and the 8 go under 7?

**Maths**

Does the 2 go under 4 or 3?

**math**

9. solve |4x + 3| = 9 + 2x and check for extraneous solutions. the first answer I got was: |4x +3| = 9 + 2x |4x| = 6 + 2x 2x = 6 x = 3 can someone help me find the other answer? thank you!

**math**

8. The half-life of a certain radioactive material is 71 hours. An initial amount of the material has a mass of 722 kg. Write an exponential function that models the decay of this material. Find how much radioactive material remains after 17 hours. Round your answer to the ...

**math**

6. The half-life of a certain radioactive material is 32 days. An initial amount of the material has a mass of 361 kg. Write an exponential function that models the decay of this material. Find how much radioactive material remains after 5 days. Round your answer to the ...

**Math**

A tank measures 30 can by 60cm by 50cm. What is the height of water in the tank when 60000 ml of water are poured into it?

**math**

O MY GOODNESS I UNDERSTAND NOW THANK YOU SO MUCH

**math**

14. Let f(x) = -2x - 7 and g(x) = -4x + 3. Find (f o g)(-5) A)23 B)-53 C)-9 D)3 please help!!

**math**

17. Let f(x) = x2 + 6 and g(x) = x+8/x . Find ( g o f)( -7) A)384/7 B)295/49 C)-57/7 D)63/55 could someone please help?

**math**

18. For the function f(x) = x2 -12, find (f o f-1)(4). A)4 B)10 C)6 D)0 help please?

**Math**

Yesterday kate and her cousin robert went out for a movie there they spent $50 in total robert spent $10 more than kate how much did kate spend?

**Chemistry**

how many grams of AlCl3 is produced if 15.5 grams of Al are reacted with excess Cl2 gas? 2Al + 3Cl2 > 2AlCl3

**math**

sorry, I meant A or B, because I am "sure" that there is a remainder from looking at the equation. I just needed someone to help go through the equation.

**math**

Divide -3x^3 - 2x^2 - x - 2 by x – 2. A. -3x2 - 8x - 17, R –36 B. -3x2 + 4x + 15, R 32 C. -3x2 + 4x + 15 D. -3x2 - 8x - 17 I'm sure it's either B or C, can someone help?

**math**

Is the relation a function? 4 -> 8 7 -> 11 10 -> 14 12 -> 10 A. yes B. no

**Geometric Sequence**

The colour of some clothing fades overtime when washed. Suppose a pair of jeansfades by 5% with each washing. To the nearest wash, how many washes would it take so that only 25% of the original colour remains in the jeans? 1. first term = 2. r = 3. tn = 4. n = I know that tn ...

**math**

The distance between town A and town B was 210 km. At 9:20 pm, a bus set off from town A to town B and a car from town B to town A. The average speed of the bus was 60 km/h, and the average speed of the car was 80 km/h. a) Calculate the time at which the car passed the bus. b...

**math**

Ava made 100 paper cranes, and Brittany made 3/4 of paper cranes Ava made. Ava gave 9/20 of her paper cranes to Brittany. Then, Brittany gave 1/4 of her paper cranes to Ava. How many more cranes did Brittany have than Ava in the end?

**Physics**

a cube slides down a frictionless incline as shown and inelastically strikes a cube at the battom of the incline that's 1/2 (one-half) it's mass. The coeff. of restitution between the two masses is 0.7. If incline is 30 cm high and table is 90cm off floor, at what ...

**physics**

a cube slides down a frictionless incline as shown and inelastically strikes a cube at the battom of the incline that's 1/2 (one-half) it's mass. The coeff. of restitution between the two masses is 0.7. If incline is 30 cm high and table is 90cm off floor, at what ...

**Math**

A person plans to invest a total of $9000 in an account that pays 3% annual interest and another account which pays 8% annual interest. How much should be invested in each account so that the total interest for one year will be $580.

**math**

the power (P) generated in a electrical circuit is proportional to the square of the current ( L amps) . when the power is 108, the current is 6 amps. a_ write down the relationship between P,L and the constant of variation k . b_ calculate the value of k c_ calculate the ...

**math**

the length ( L cm) of an edge of a cube is proportional to the cube root of its mass ( M grams).It is known that if L= 15, then M=125. let K be the constant of variation. CALCULATE THE VALUE OF K

**Physics**

Blood flows in an aorta of radius 4.62mm at 35.0cm/s. Calculate the volume flow rate. Although the cross-sectional area of a capillary is much smaller than that of the aorta, there are many capillaries, so their total cross-sectional area is much larger. If all the blood from ...

**Physics**

Thank you!

**Physics**

I keep getting .154

**Physics**

Thank you so much! And What distance, d, from the edge of the table does the block hit the floor?

**Physics**

A 0.294-kg box is placed in contact with a spring of stiffness 3.792×102 N/m. The spring is compressed 1.42×10-1 m from its unstrained length. The spring is then released, the block slides across a frictionless tabletop, and it flies through the air. The tabletop ...

**Chemistry**

The pH of human blood needs to be between 7.35 and 7.45. You want to prepare a buffer solution that gives a pH of 7.40. You decide to use a sodium phosphate buffer: the acid is H2PO− 4 and the conjugate base is HPO2− 4 . You want the concentration of the acid to be...

**Math**

Thank you£¡

**Math**

I don¡¯t know how to slove this problem can someone help me£¿ The shorter leg of a 30¡ã60¡ã90¡ãtriangle is 2.5 feet long.Find the perimeter.

**Physics**

Consider a metal rod that is 1.42 m in length at a temperature of 14.4°C. The coefficient of linear expansion is 5.22×10-5°C-1. What is the change in length of the rod as temperature increases from 14.4°C to 52.0°C.

**Language arts**

1.C 2.D 3.A 4.D

**Physics**

The volume flow rate in an artery supplying the brain is 4.59E-6 m3/s. If the radius of the artery is 5.33 mm, determine the average blood speed.

**Physics**

A block of mass M=0.525kg is floating stationary in a beaker of water. A string connected to the bottom of the beaker holds the block in place. The tension in the string is 7.10 N. The bottom of the block is floating a distance h=1.66cm above the bottom of the beaker. What is ...

**Chemistry**

I'm sorry the full question was: 1. If the initial H2PO− 4 concentration is 0.0100 M, what is the initial concentration of HPO2− 4 that will give a pH of 7.40? 2. What is the maximum molarity of acid that this buffer can neutralize without the pH dropping below...

**Chemistry**

The pH of human blood needs to be between 7.35 and 7.45. You want to prepare a buffer solution that gives a pH of 7.40. You decide to use a sodium phosphate buffer: the acid is H2PO−4 and the conjugate base is HPO2− 4. You want the concentration of the acid to be 0...

**Math**

A high school has 438 students with about the same number of males and females. Describe a simulation to predict how many of the first 50 students who leave school at the end of the day are female.

**Math**

Talia tossed a penny many times. she got 40 heads and 60 tails. she said the experimental probability of getting heads was 40 over 60. Explain and correct her error.

**math**

Shoot. I meant to say how to write this equation in standard form: y=(x+1)(x-1)(x-1)

**Precalculus**

A population of bacteria has exponential growth and will double after 10 hours. Find the growth rate to the nearest hundredth.

**Physics**

A spring loaded ballistic pendulum gun requires an increasing force to load. When loading a ball of mass 0.054 kg, the spring is compressed 7.00 cm, the gun is fully loaded, and the force required is 70.0 N. a) Calculate the work required to load the gun. b) Calculate the ...

**Physics**

A pendulum clock can be approximated as a simple pendulum of length 1.03 m and keeps accurate time at a location where g = 9.82 m/s2. In a location where g = 9.77 m/s2, what must be the new length of the pendulum, such that the clock continues to keep accurate time (that is, ...

**Stats**

{Exercise 7.11} The following data are from a simple random sample. 3, 8, 11, 6, 11, 15 What is the point estimate of the population mean? 9 What is the point estimate of the population standard deviation (to 1 decimal)?

**Geometry**

a jewlery box in the shape of a rectangle prism has a volume of 90in.3 and a height of 2 1/2 in, What are possible demensions for the length and width of base

**Physics**

A horizontal circular platform (m = 110.1 kg, r = 3.21m) rotates about a frictionless vertical axle. A student (m = 98.3kg) walks slowly from the rim of the platform toward the center. The angular velocity, omega, of the system is 3.9 rad/s when the student is at the rim. Find...

**chemistry**

If 5.40 kcal of heat is added to 1.00 kg of water at 100⁰C, how much steam at 100⁰C is produced? Show all calculations leading to an answer. Please help?

**chemistry**

You have two sealed jars of water at the same temperature. In the first jar there is a large amount of water. In the second jar there is a small amount of water. Using 3 -4 sentences explain how the vapor pressure of water in the first jar compares with the vapor pressure of ...

**Math**

Which hand has covered more distance from the 12 on a clock, the minute hand at 4:00 or the second hand at 15 seconds past? Write a fraction inequality to support your answer.

**Trig**

Find the exact values of sec(x)=7. I know that cos(x)=1/7. I know that sin(x)= sqrt(1-91/4900). I know that tan(x)=1. I know how to do the problem but I'm not really sure why, and I'd like to know. I got 4sqrt(3). Please help!

**Calculus**

I got the second answer. Still confused on the first one.

**Calculus**

Find the exact value of cot(arcsin(12/13)) and cos(arcsin(1.7/2)) I know that cos(arcsin(x))=sin(arccos(x))=sqrt(1-x^2). I'm having more difficulty with the first one. Please help! Thank you

**Calculus**

How do I tell the difference between a non conic function and a conic function by looking at an equation?

**chemistry**

A gas occupies 5.65 L at 808 torr and 17◦C. What volume will it fill if the pressure is changed to 730 torr and the temperature is raised to 51◦C?

**Algebra**

Find two consecutive even integers such that the square of the lesser integer increased by twice the greater integer is 364.

**Physics**

Just saw your reply, bobpursley. I will show you my work in a few minutes. Thank you

**Physics**

I got a, but can't figure out the rest of the questions. Please help! Thank you

**Physics**

A high-speed sander has a disk 5.70 cm in radius that rotates about its axis at a constant rate of 1120 revolutions per minute. a.) Determine the angular speed of the disk in radians per second. b.) Determine the linear speed of a point 2.40 cm from the disk's center. c.) ...

**Physics**

How do you turn revolutions into radians? Please help!

**Physics**

A wheel has a radius of 5.22 m. a.) How far (path length) does a point on the circumference travel if the wheel is rotated through an angle of 34.3°? b.) How far does a point on the circumference travel if the wheel is rotated through an angle of 34.3 rad? c.) How far does...

**Physics**

A pulsar is a rapidly rotating neutron star that continuously emits a beam of radio waves in a searchlight manner. Each time the pulsar makes one revolution, the rotating beam sweeps across the earth, and the earth receives a pulse of radio waves. For one particular pulsar, ...

**Physics**

A block of mass 0.61kg starts from rest at point A and slides down a frictionless hill of height h. At the bottom of the hill it slides across a horizontal piece of track where the coefficient of kinetic friction is 0.40. This section (from points B to C) is 4.73m in length. ...

**Physics**

In a skating stunt known as "crack-the-whip", a number of skaters hold hands and form a straight line. They try to skate so that the line rotates about the skater at one end, who acts as the pivot. The skater farthest out has a mass of 76.7 kg and is 6.18 m from the ...

**Physics**

A 9.37 kg monkey is hanging by one arm from a branch and swinging on a vertical circle. As an approximation, assume that the radial distance between the branch and the point where the monkey's mass is located to be 86.8 cm. As it swings through the lowest point on the ...

**Physics**

A car travels at a constant speed around a circular track whose radius is 2.59 km. The car goes once around the track in 380 s. What is the magnitude of the centripetal acceleration of the car?

**Physics**

Read the equation wrong, I got it. Sorry!

**Physics**

I know that Fc= mv^2r, and I keep getting r=.7154 but it says it's incorrect. What am I doing wrong? Help please!

**Physics**

At an amusement park there is a ride in which cylindrically shaped chambers spin around a central axis. People sit in seats facing the axis, their backs against the outer wall. At one instant the outer wall moves at a speed of 3.21 m/s, and an 75.7 kg person feels a 558 N ...

**chem**

Arrange the following compounds in order of increasing boiling point. butanal 1-butanol diethylamine tartaric acid butane butanoic acid and can you please explain why?

**Math**

Points J and K, plotted on the coordinate grid, are two vertices of rectangle JKLM. Rectangle JKLM has an area of 7 square units. Point J is located at (2, 1) and point K is located at (-5,1) each vertex of the rectangle is located at a point that has integer coordinates. Part...

**chemistry**

The formation constant* of [M(CN)4]2– is 7.70 × 1016, where M is a generic metal. A 0.170-mole quantity of M(NO3)2 is added to a liter of 1.040 M NaCN solution. What is the concentration of M2 ions at equilibrium?

**Physics**

Block B has a mass of 3.40kg and is moving to the left at a speed of 4.20m/s. Block A has a mass of 6.40kg and is moving to the right. The two blocks undergo a perfectly inelastic collision. What should the velocity of the Block A be in order to have the two blocks move to the...

**Physics**

Block B has a mass of 2.20kg and is moving to the left at a speed of 2.30m/s. Block A has a mass of 2.70kg and is moving to the right. The two blocks undergo a perfectly inelastic collision. What should be the velocity of Block A in order to have the two blocks remain at rest ...

**Math**

If adriana drew 20 pitchers and 3/4 of them are in art class how many pitchers did adriana draw in art class

**Physics**

A 63-kg ice-skater glides with a speed of 10 m/s toward a 14-kg sled at rest on the ice. The ice-skater reaches the sled and holds on to it. The ice-skater and the sled then continue sliding in the same direction in which the ice-skater was originally skating. What is the ...

**Physics**

A 64.8 kg ice skater is skating along in a straight line (in the positive direction) at 9.2 m/s when he bends down and scoops up his 24.4 kg doggy sitting still on the ice. What will be the new velocity of the dog-n-skater?

**Physics**

A car of mass 422 kg is moving 36.0° North of East at a speed of 15.4 m/s. What is the magnitude of the momentum of the car? (magnitude - how big is it? ignore direction). What is the east-west component of the momentum of the car? I already figured out the first question ...

**Physics**

A car of mass 422 kg is moving 36.0° North of East at a speed of 15.4 m/s. What is the magnitude of the momentum of the car? (magnitude - how big is it? ignore direction)

**Physics**

Suppose a 300–g kookaburra (a large kingfisher bird) picks up a 84.0–g snake and raises it 2.30 m from the ground to a branch. How much work did the bird do on the snake? I know that W=deltaPE, and PE=mgh. I keep getting 1046.64. Please help!

**calculus**

water is being siphoned from a cylindrical tank of radius 10m into a rectangular tank whose base measures 20m by 15m. if the depth of the water in the cylindrical tank in decreasing at a rate of 2m/s, at what rate is the depth of the water increasing in the rectangular tank

**Fractions**

3 i

**Math**

Marco and his friends bought game tokens for $15 and three admission ticket. Determine if each statement below is true or false. If each admission ticket costs $2.50, then Marco and his friends spent $22.50 in all. True or False

**Math**

its D

**Algebra**

Two trains, one going from Boston to New York and the other going from New York to Boston, started their trips at exactly same time. Speed of the first train was 10 miles per hour less than twice the speed of the second train. How far from Boston station have they met, if the ...

**Physics**

3. A skater with an initial speed of 7.6 m/s is gliding across the ice. The coefficient of friction between the ice and the skae blades is μk=0.1. a. Find acceleration of the skater b. How foar will the skater travel before coming to rest

**Math**

Six year old Rosie wants to write down all counting numbers up to one thousand. When she finished writing 12, she had 15 digits. Rosie gave up after she had correctly written 2358 digits. What was the last number she wrote?

**Physics**

In the nail puller shown in the figure below you exert a force 49.6 cm from the pivot and the nail is 1.90 cm on the other side. What minimum force must you exert to apply a force of 1460 N to the nail to pull the nail up?

**Physics**

A 83.2-kg man stands on his toes by exerting an upward force through the Achilles tendon, as in the figure below. What is the force in the Achilles tendon if he stands on one foot?

**Physics**

Even when the head is held erect, as in the figure below, its center of mass is not directly over the principal point of support (the atlant-ooccipital joint). The muscles at the back of the neck should therefore exert a force to keep the head erect. That is why your head ...

**Physics**

What is the magnitude of the momentum of the 0.057-kg tennis ball when it travels at a speed of 29 m/s? Earth is the frame of reference.

**Physical science**

a balloon has a volume of 0.5 L at 20 degrees celsius. what will the volume be if the balloon heated to 150 degrees celsius? assume constant pressure and mass. I got 0.7218 L.

**Math**

A piece of ribbon is 7 1/2in. long. If a piece 2 3/16in. long is cut off, how long is the remaining piece?

**Physics**

Block A sits on a horizontal tabletop. There is friction between the surface and Block A. The string passes over a frictionless, massless pulley. Block B hangs down vertically. When the two blocks are released, Block B accelerates downward at a rate of 2.030 m/s2. What is the ...

**Physics**

The initial velocity of a 2.75 kg block sliding down a frictionless inclined plane is found to be 1.25 m/s. Then 1.05 s later, it has a velocity of 5.31 m/s. What is the angle of the plane with respect to the horizontal? I keep trying to use sine and cosine but I can't ...

**chemistry**

why are there only certain colours in an atomic emission spectra?

**Math**

The answer is 97 because it's the only prime number between 60 and100