# Posts by MIchael

Total # Posts: 1,989

**Chemistry**

@DrBob222: It's sodium carbonate. And the backyard scientist on Youtube has a video on pouring molten salt into a fish tank, which you can watch "before your eyes in living color".

**Chemistry **

When you pour molten salt(NaCl) into the water, it explodes. But if you pour molten sodium bicarbonate into the water, there's no explosion. Why is this happening???? I'm so confused and I have seen a video of this actually happening. Please help!

**Physics**

What is a fatigue fracture

**Math**

Construct kite ABCD with adjacent sides AB egual to 6cm and BC egual to 9cm.BAC=60cm

**math 7th grade**

correction: Doug spent $90 over the week end. He spent 1/4 of it on a CD and 1/5 on movie ticket. how much money did he have at the start of the weekend?

**math**

Doug earned $40 from weekend job. he spent 1/4 of it on CD and 1/5 on movie ticket. how much money did he have at the start of the weekend?

**Math**

Three out of 200 machine parts were found to be defective. About how many parts would be expected to be defective out of 2500 parts? A. 15 B. 30 C. 38 D. 67

**Math - combinatorics/ permutations**

Yep spot on

**English**

1. yes 2. no, could've also finished it

**chemistry**

How many grams of iron(II) oxalate dihydrate, Fe(C2O4)·2H2O,mass can be produced when a student begins the synthesis with 3.238 g of ammonium iron(II) disulfate hexahydrate, (NH4)2Fe(SO4)2·6H2O?

**maths**

i have tens ones and tenths.my digits are next door numbers and they add up to9 what number am i

**science**

1) At body temperature of 36.5 ° C the osmotic pressure of the blood is of 7.80 atm. Calculate the mass of glucose (C6H12O6) that must be added to one liter of a solution containing 5 g / L of NaCl to be able to inject directly into a vein.

**Science **

An eagle flying along a horizontal path drops a small snake from a height of 6.5 m while travelling 5.0 m/s. How far does the snake travel horizontally before it hits the ground below? G: R: E: S: A:

**engineering mathematics**

f=ma a=m/f a=60*20/200 a=6

**Chemistry**

A reaction requires 22.4 L of gas at STP. You have 30.5 L of gas at 101.5 kPa and 373 K. Which of the following statements is true? (Use the ideal gas law: PV = nRT where R = 8.31 L-kPa/mol-K.) You will have excess gas for the reaction. You will have enough gas for the ...

**sciance**

is a car faster than usain bolt in a 100m race

**English**

I've read the entire offal book im just not sure about these 4 answer. No one can help me tho because no one else has ever read this god offal book.

**English**

Ethan Frome test please check my answers and correct them if they are wrong 4. Which word best describes the atmosphere, or mood, of the Prologue and Chapter I? A. jolly B. comfortable C. severe D. superstitious B is wrong Answer c 11. What kind of conflict describes the ...

**English**

Ethan Frome test please check my answers and correct them if they are wrong 4. Which word best describes the atmosphere, or mood, of the Prologue and Chapter I? A. jolly B. comfortable C. severe D. superstitious B is wrong Answer c 11. What kind of conflict describes the ...

**English**

Ethan Frome test please check my answers and correct if they are wrong 4. Which word best describes the atmosphere, or mood, of the Prologue and Chapter I? A. jolly B. comfortable C. severe D. superstitious B is wrong Answer c 11. What kind of conflict describes the struggle ...

**Chemistry**

Assume that 5.00 grams of zinc react with excess HCl according to the following equation: Zn + 2HCl = ZnCl2 + H2 The hydrogen was collected over water at 20.0C and the prssure of the atmosphere is 751 mmHg. The pressure of the water vapor at 20C is 17.5 mmHg. How many moles of...

**math**

10

**LA**

PLEASE check my answer this is my last test and i d not want to mess up PLEASE 1. Which sentence contains an opinion? (1 point) Thomas Jefferson supported American independence from Great Britain. He was a lawyer in his home state of Virginia. Jefferson authored the ...

**MAth**

I got 55% but do not take my word. I think you should wait for the answer from an actual tutor. I did 50/90 which led me to 55% of babies that were born yesterday were girls. I would still wait for an answer from someone else and not put that until someone with higher ...

**Geometry**

A tree stands 22 feet tall and is 382 feet from a building. The tree casts a shadow that is 40 feet long. How tall is the building? I got 211 feet, but I do not think that is correct. Can you tell me what I am doing wrong? I set it up like this h/382=22/40 Thank you!

**Geometry Honors**

Thank you!

**Geometry Honors**

A tree stands 22 feet tall and is 382 feet from a building. The tree casts a shadow that is 40 feet long. How tall is the building?

**social studies**

and second of all you can not talk to me like that.

**social studies**

first of all I was not talking about 2. I was talking about 4.

**social studies**

means

**social studies**

ok i know what involuntary

**social studies**

hellooooo?!

**social studies**

kinda?

**social studies**

1) BLANK are people who move into one country from another. A) Emigrants B) Immigrants C)Urbanites D) Nomads 2. One of the largest involuntary migrations in history was the transatlantic A) Irish migration. B) immigrant wave. C) slave trade. D) migration of Hindus from ...

**Maths**

In a triangle with angles ?,?,? and opposite sides a, b, c you are given: ?=35°, ?=100°, b=40. Find all missing lengths and angles as well as the area correct to 1 decimal place.

**maths**

The level of oil in a bottle is at the 1/2-mark. More oil is poured in until it is at the 7/8- mark. What fraction of the bottle is occupied by the additional amount of oil. Pls show all working.

**chemistry**

arrangement of the following gas molecule in their increasing average speed at the same temperature. O2, N2, H2O,CO2,NO2 and Cl2

**maths**

Consider the 4 points A(1,5), B(-4,6), C(0,0), D(-12,12). Find the gradients of the lines: (a) BD

**Math**

it maybe 3,5,15,105

**URGENT ANY PhYSIcs teacher help thouroighly pls**

The coefficiant of friction between rubber tires and wet pavement is 0.5. Breaks are alllied to a 750kg car, intitally travelling at 30 m/s and the car skids to a stop. What is the magnitude and direction of the acceleration. Ik the magnitude and i kinda get how to do the ...

**physics**

A uniform ladder of length 20.0m and weight 750 N is propped up against a smooth vertical wall with its lower end on a rough horizontal surface. The coefficient of friction between the ladder and this horizontal surface is 0.40. (b) Work out and add the numerical values of ...

**Physics**

A uniform ladder of length 20.0m and weight 750 N is propped up against a smooth vertical wall with its lower end on a rough horizontal surface. The coefficient of friction between the ladder and this horizontal surface is 0.40. (b) Work out and add the numerical values of ...

**PHYSICS**

A uniform ladder of length 20.0m and weight 750 N is propped up against a smooth vertical wall with its lower end on a rough horizontal surface. The coefficient of friction between the ladder and this horizontal surface is 0.40. (b) Work out and add the numerical values of ...

**maths**

By making the substitution u=ln x show that the following equation has exactly one real-number solution: -12/ln x + ln x^4 = -9

**maths**

(a) Let u=7^x. Using the rules for powers show that i) 7^x-1 = u/7 and ii) 7^2x-1 = u^2/7 (b) By making the substitution u=7^x and using part (a), derive a hidden quadratic equation 7^2x-1 +4×7^x-1 - 1/14 = 0 and hence find all solutions to the above equation.

**maths**

(a) Solve the following equations for x where possible, giving your solutions correct to three decimal places. (i) 3^x+1 -1=5 (ii) 3×4^x =4×4^1-2x (b) Confirm that any solutions you found in part (a) are (approximately) correct by sub-situiting into the original ...

**maths**

Write down the sum and product of the roots of the following quadratic polynomials: (a) 3x^2 - 6x - 7 (b) 3x^2 + 6x + 7

**maths**

Determine the nature of the roots of the following quadratic equations: (a) 3x^2 - 6x + 7 = 0 (b) 3x^2 + 6x - 7 = 0 (c) -5x^2- x/5 = 0 (d) 4x^2 - 28/3x + 49/9 = 0

**maths**

Solve the simultaneous questions: (a) x+y+z=-3 (1) x-y-2z=13(2) y-4z=25 (3) (b) x+2y+3z=-14 (1) 2x+3y-z=13 (2) 3x-y+2z=-7 (3)

**maths**

1a) Solve the each of these equations by factorising the left hand side into a product of linear factors: (i) x^2 - 6x - 40 = 0 (ii) 3x^2 + 20x - 7 = 0 (b) For each question in part (a), check your solutions by substituting them back into the equation. 3. Solve each equation ...

**maths**

Write down the sum and product of the roots of the following quadratic polynomials: (a) 3x^2 - 6x - 7 (b) 3x^2 + 6x + 7

**maths**

Determine the nature of the roots of the following quadratic equations: (a) 3x^2 - 6x + 7 = 0 (b) 3x^2 + 6x - 7 = 0 (c) -5x^2- x/5 = 0 (d) 4x^2 - 28/3x + 49/9 = 0

**maths**

Solve the simultaneous questions: (a) x+y+z=-3 (1) x-y-2z=13 (2) y-4z=25 (3) (b)x+2y+3z=-14 (1) 2x+3y-z=13 (2) 3x-y+2z=-7 (3)

**maths**

1a) Solve the each of these equations by factorising the left hand side into a product of linear factors: (i) x^2 - 6x - 40 = 0 (ii) 3x^2 + 20x - 7 = 0 (b) For each question in part (a), check your solutions by substituting them back into the equation. 3. Solve each equation ...

**history**

Article I, Section 8 of the U.S. Constitution grants Congress the power to do all of the following EXCEPT ____.

**Jefferson**

A car is traveling at 40 miles per hour. Write a rational expression that gives the time that it takes the car to travel Upper M miles.

**Math**

How do I arrange these in order from the smallest to greatest 5/6, 7/12, 5/8, 23/48

**Algebra**

Which property is illustrated by the following statement? 2(-3/9)=(-3/9)2 A. Associative property of addition. B. Commutative property of multiplication. C. Inverse property of multiplication. D. Commutative property of addition.

**Algebra**

Which property is illustrated by the following statement? 2(-3/9)=(-3/9)2 A. Associative property of addition. B. Commutative property of multiplication. C. Inverse property of multiplication. D. Commutative property of addition.

**Algebra**

Which property is illustrated by the following statement? 2(-3/9)=(-3/9)2 A. Associative property of addition. B. Commutative property of multiplication. C. Inverse property of multiplication. D. Commutative property of addition.

**Algebra**

Which property is illustrated by the following statement? 2(-3/9)=(-3/9)2 A. Associative property of addition. B. Commutative property of multiplication. C. Inverse property of multiplication. D. Commutative property of addition.

**Algebra**

Which property is illustrated by the following statement? 2(-3/9)=(-3/9)2 A. Associative property of addition. B. Commutative property of multiplication. C. Inverse property of multiplication. D. Commutative property of addition.

**math**

each student needs 2/5 of a cup of play dough to build a house. How many cups of play dough are needed for 9 students?

**science**

how much force is needed to accelerate a 7.1 kg skier at 4 m/s/s?

**Government**

1. Which of the following is true about the formal amendment process for the Constitution? A. Only citizen may propose an amendment. B. Only Congress may propose an amendment. C. Both houses of Congress may pass a resolution to propose an amendment. D. The president can Vito ...

**Geometry**

Do you go to Connections academy in the 10 th

**American government**

That's your problem. Get your own amswers and stop trying to cheat.

**math**

Indira reacts that the actual difference of 19-7.82 will be greater than the estimate of 19-8=11.Is Indira correct?Explain how Indira might have arrived at the prediction without subtracting the actual numbers.

**English**

Robert Borden

**6**

The pet store aquarium holds 32 fish. Today 13 angelfish and 19 are clownfish to the total number of fish in the aquarium

**Calculus AB**

A rectangle is inscribed in a right triangle with legs of length 5 and 12. The sides of the rectangle are parallel to the legs of he triangle. Find the dimensions of the rectangle that has the largest area?

**Calculus AB**

A 5.5 foot man walks away from a 12 fokt lampost at a constant speed. At a given moment, let l be the length of the man's shadow (along the ground) and ket x be his distance from the lampost. Sketch a figure that represents the problem Express l in terms of x

**Calculus AB**

The height h of a closed cylindical tank is 4 times longer than he radius r. Write the volume of the tank as a function of r. Write the total surface area of the tank in terms of h.

**Calculus AB**

Water pours at a constant rate into a conical tank of height 10 feet and radius 4 feet. Let V, h and r be the volume, height, and radius if the water in the tank at a particular time t. Express the volume of the water in the tank at any time t as a function of h only.

**Calculus AB**

Let f be the function that is given by f(x)=(ax+b)/(x^2 - c). It has the following properties: 1) The graph of f is symmetrical with respect to the y-axis 2) The graph of f has a vertical asymptote at x=2 3) The graph of f passes through the point (-1,3) Determine the values ...

**Calculus AB**

Theta is an angle between the lines L1 and L2 with the slopes m1 and m2. Prove that tan theta= (m2 - m1)/(1+m2m1).

**Calculus AB**

If r and s are roots of the pokynomial equation x^2 + bx + c, show that b=-(r+s) and c=rs

**Calculus AB**

Solve graphically (x-2)^3(x+4)(3-x)^2(x+1)^4 <0

**Calculus AB**

A hiker walks due east for 40 minutes, then changes course by going South 25 degrees West. After 20 minutes, he changes course again, this time at South 75 degrees East. He goes through this path for one hour after which he heads north reaching his final destination in 15 ...

**Calculus AB**

One of the equal angles of an isosceles triangle is 55 degrees. If the base is 20 cm, what is the perimeter and the area?

**Calculus AB**

Thanks a bunch. And I got 4.967 meters as the final answer based off of what you gave me.

**Calculus AB**

From a height of 10 meters in the third floor of an apparent that building, the angle of depression of two cars moving on the same lane and in the same lane and in the same direction measure 29.5 degrees and 38.2 degrees. How far are the two cars from each other? This ...

**Calculus AB**

What is an algebraic expression for cot(arccos ((x+1)/2)?

**Calculus AB**

Without using a calculator, what is the exact value of sec(arctan(12/5)) - sin(arccot(3/4))

**Math CSET**

A student scores 96 on a test. The class average is 84, with a standard deviation of 4 points. What percentage of the class scored below this student? I understand the 96-84/4 part to obtain a z-score of 3. What I do not understand is, if I do not have access to a z-score to ...

**Maths**

if a spinner is divided into 6 equal parts ,when it's spun, what is the probability of spinning on 4?

**Physics**

You jump across and down a crevasse from rest. You land on the other side at a speed of 10.5 m/s directed 67.6° below the horizontal. The other side is 4 meters lower. How wide was the crevasse? No Idea if I am doing this right. But so far what I done was 10.5Sin(67.6...

**Physics**

You jump across and down a crevasse from rest. You land on the other side at a speed of 10.5 m/s directed 67.6° below the horizontal. The other side is 4 meters lower. How wide was the crevasse? No Idea if I am doing this right. But so far what I done was 10.5Sin(67.6...

**physics**

one cubic meter of water hass a mass of 1.0x10^-3. (a) determine the mass of 1.0 m^3. (b) assu!ing biological substance are 98% water, estimate the mass of cell with a 1.0 micrometer dia!eter, a human kidney and a fly. assume a kidney is roughly a sphere with radius of 4.0 cm...

**Physics**

16.8seconds

**Physics**

16.8mm

**Physics**

A 10 kg block is towed at a 30° incline with respect to the horizontal the rope is parallel to the incline and has attention 100 N assume that the block starts from rest at the bottom of the hill and neglect friction how fast is the block moving after 40 m up the hill

**pre-algebra**

yes

**pre-algebra**

is (-1, 5) a solution to 2 x = y - 7 and 2 y = - x + 9

**IT**

why is system Burn-in important?

**math**

Find dy/dx and d2y/dx2. x = e^t, y = te^t

**Life orientation**

Describe the three human rights violations

**English**

As the world influence shift so will the language. To teach a language is to aid communication between individuals. Its not whether there is a right or wrong. For example there can be a mathematical language with its own vocabulary that allows mathematicians to communicate ...

**social studies**

What they are referring to is the battle at the Alamo which is in San Antonio TX. During this time a 100 Texas soldiers fought against approximately 1,500 Mexican soldiers. The did loose however after 10 DAYS, they had killed or injured more then 600 Mexican Soldiers. From ...