# Posts by kid

Total # Posts: 136

**Math**

100m/16.30s = 60m/x x = 9.78s It would take 9.78s to run 60m.

**Physics**

Sorry, I meant to say towards the end "more specifically [...] which is where I AM stuck"

**Physics**

An electron is accelerated from rest through a potential difference of 1.40*10^5 V. What is its speed? So there were also two parts before to this question: the relativistic kinetic energy in eV (which I correctly found to be just 1.40*10^5 eV) and its relativistic total ...

**Physics**

For a rectangular metal surface with dimensions 5 cm by 3 cm, the threshold wavelength for the photoelectric emission of electrons is 246.0 nm. (a) Calculate the work function of the metal surface. So I planned to use: hf - workfunction = eV Then I replace f with c/lambda, ...

**Physics**

So in the end, it doesn't really matter at all which one I use? Is there ANY difference that I'll get when solving for unknown values depending on which one I use?

**Physics**

Is one of the formulas used in "thin film" interference problems 2t = (m + 0.5)(lambda/n_film) OR 2t = (m - 0.5)(lambda/n_film), where t is the thickness of the film? I might have copied my notes down incorrectly in class, because according to internet sources, it is...

**Physics**

How did you get "sqrt 2" from "sqrt(tension/mass per unit length)"?

**Physics**

A cord has two sections with linear densities of 0.10 kg/m and 0.20 kg/m respectively. An incident wave, y(x,t) = 0.050sin(6.0x - 12.0t), where x is in meters and t in seconds, travels from the lighter cord to the heavier one. What is the wavelength of the wave in each section...

**Physics**

The PV diagram shows the compression of 44.1 moles of an ideal monoatomic gas from state A to state B. Calculate Q, the heat added to the gas in the process A to B. Data: PA= 1.90E+5 N/m^2 VA= 1.93E+0 m^3 PB= 1.31E+5 N/m^2 VB= 7.90E-1 m^3. deltaE_int = Q-W deltaE_int = (3/2)((...

**Physics**

A ping pong ball of mass m = 4.9 gram is precisely measured in position to an accuracy of 10^-10 m. What must be the uncertainty in its velocity (in 10^-20 m/s)? (delta_x)(delta_p) > h/4pi (delta_x)(m)(delta_v) > h/4pi (10*10^-10)(0.0049kg)(delta_v) > (6.63*10^-34)/...

**Physics**

In a setup/situation involving buoyancy, let's say there are two blocks, where one is of styrofoam and the other is aluminum, both placed in a fluid (for example: honey). The aluminum block is placed on the styrofoam block. How can I calculate the buoyant force acting on ...

**Physics**

A sphere of mass of m = 1.69 kg is first placed directly on the plate of an electronic scale. The scale shows 16.58 N as the weight of the object. A large beaker containing a liquid with a density of 783 kg/m^3 is then placed on the scale and the scale is tared (i.e. zeroed to...

**Physics - Buoyancy**

A sphere of mass of m = 1.69 kg is first placed directly on the plate of an electronic scale. The scale shows 16.58 N as the weight of the object. A large beaker containing a liquid with a density of 783 kg/m^3 is then placed on the scale and the scale is tared (i.e. zeroed to...

**Physics**

An anti-hydrogen atom is made using an antiproton and a positron. The spectral lines corresponding to the energy transitions of the positron are then measured. Which of the following statements, if any, are true? A) The measured spectral lines will all be identical to those of...

**Physics - Fluids**

A helium balloon (mass including fill gas 2.1 g) is tied to a long string (mass per unit length is 3.1*10^2 g/cm, i.e., one cm of the string has a mass of 3.1*10-2 g). It rises to a height x of 210 cm, with the remainder of the string laying on the floor. If the density of air...

**Light Intensity on a Screen**

A set of narrow vertical slits is located a distance D from a screen. All the slits have the same width, equal to 35.1 ?m. The intensity pattern in the figure is observed when light from a laser passes through the slits, illuminating them uniformly. How many slits are ...

**Slit width in double slit experiment**

Thank you, and I would just like to know how you are able to post links, since this site always says that I am unable to.

**Slit width in double slit experiment**

Link to image relevant to this problem (Add a dot after "1h3" and "googleusercontent" -> lh3googleusercontentcom/rL6zLQRGjdYSHMfsvAN_a4E_s3MARseiAw-KmFUfP5sp5nmp3c7E43zWO9_3ZrWwez6iZQ=s108 Light of wavelength 550 nm passes through a double slit, yielding...

**Wavelength of a light**

Nevermind, apparently that distance value was 0.043 which I was not certain before because it was based on more of an estimation rather than a definite value. So all good now!

**Wavelength of a light**

Oh wait, that might not have been posted properly. Just put a dot after "Ih3" and "googleusercontent". I needed to show you the image because I feel that is the issue, that I may not have correctly interpreted the distance of the first m of diffraction.

**Wavelength of a light**

[Replace each space with a dot(.)] Link to image related to this question-> lh3 googleusercontent com/TjcBG60hMmLnA7rwTp0hIb4SzI2gqZtebe8g3cjQ1rf8xd0HXulzCNZTrTrVzw0zPyNC=s147

**Wavelength of a light**

A single vertical slit of width 24000 nm is located 2.10 m from a screen. The intensity pattern below is observed. The distances on the screen can be measured from the scale. Each tick mark is equal to 1 cm. Intensity is displayed along the y-axis. What is the wavelength of ...

**Physics - Center of Mass**

A square aluminum plate (volume mass ? = 2700 kg/m^3) has dimension L = 4.8 m and e = 0.9 m. A cylinder of radius R = 1.5 m and at a distance d = 1.2 m from the center of the plate and at 20 deg with the horizontal, is removed from the plate. Find the centre of mass of this ...

**Physics - Center of Mass**

But I still don't know how to use the equation in order to find the x-coordinate of the center of mass of the rod. I only have the total mass of the rod = 0.1923 kg but I don't know what to do with that value now.

**Physics - Center of Mass**

A long thin rod lies along the x-axis from the origin to x=L, with L= 0.830 m. The mass per unit length, lambda (in kg/m) varies according to the equation lambda = lambda0(1+1.110x^3). The value of lambda is 0.200 kg/m and x is in meters. Calculate the x-coordinate of the ...

**Physics**

A long thin rod lies along the x-axis from the origin to x=L, with L= 0.830 m. The mass per unit length, $\lambda$ (in kg/m) varies according to the equation $ \lambda = \lambda_0 (1+1.110x^3). The value of $\lambda_0$ is 0.200 kg/m and x is in meters. Calculate the total mass...

**Physics - Center of Mass**

A square aluminum plate (volume mass ? = 2700 kg/m^3) has dimension L = 4.8 m and e = 0.9 m. A cylinder of radius R = 1.5 m and at a distance d = 1.2 m from the center of the plate and at 20 deg with the horizontal, is removed from the plate. Find the centre of mass of this ...

**Physics - Capacitance**

In the case of having two plates of a capacitor, in the formula for capacitance C = (Epsilon)(A/d), is A the sum of the areas of each plate or just the area of one plate? And if it is the latter, then it can be assumed that both plates have the same area, right?

**Physics - Voltage across a wire of unknown length**

Four copper wires of equal length L are connected to a 100V source. Their cross-sectional area are 1cm^2, 2cm^2, 3cm^2, and 4cm^2. Find the voltage across the 3cm^2 wire. Leave your answer in terms of L, it should cancel out. - So I tried using and equating various relevant ...

**Physics - Calculating work required**

Alrighty, thank you!

**Physics - Calculating work required**

Two equipotential surfaces are shown. If Va = -5V and Vb = -15V, find the work needed to move a -2?C charge from A to B along the indicated path. - First of all, does the path of the charge going from A to B matter or can I just calculate using the "distance" ...

**math**

If you're solving for percentage: 75% of 80 = 60

**Physics - Electric force, field, and potential**

A 2?C charge is positioned at x = -0.8m and another 2?C charge is positioned at x = 0.8m. A positive test charge of q = 1.28*10^-18C is positioned at the origin x = 0m. Find (a) the electric force exerted on q, (b) the electric field at the origin, and (c) the electric ...

**Physics - Potential Difference**

An electron moving in the + x-direction has an initial speed of 3.7*10^6 m/s at the origin. Its speed is reduced to 1.4*10^5 m/s at x = 2cm. Calculate the potential difference between the origin and that point. Which point is at the higher potential? My work and calculations...

**Physics - Collisions**

A big toy school bus rear-ends a small toy school bus initially at rest. The bigger bus is several times heavier than the smaller one. Which of the following statements are true if the collision is totally inelastic? 1. The big bus exerts the same amount of force on the small ...

**Calculus - Optimization**

A Norman window has the shape of a semicircle atop a rectangle so that the diameter of the semicircle is equal to the width of the rectangle. What is the area of the largest possible Norman window with a perimeter of 38 feet?

**Math - Antiderivatives/Integrals**

Find the function with derivative f?(x)=e^(9x) that passes through the point P=(0,4/9).

**History**

PLEASE!!! I need help its overdue and I haven't seen the answer anywhere. It for connexus. PLEASE HELP!!!

**Math - Composition of Functions**

Express the function f(x) = 1/x+1 in the form goh. If h(x) = x+1, find the function g(x).

**math**

what is 843,208,732,833?

**Math**

Total balloons = 12 Let x = # of green balloons 12 = 5+3+x 12 = 8+x x= 4 # of green balloons/total balloons = 4/12 = 1/3 1/3 of the balloons are green.

**Physics**

But my final answer is correct?

**Physics**

NASA wants to build a centrifuge to train its astronauts to handle the strong accelerations they will experience when the space shuttle lifts off. A composite material capable of withstanding a normal force of 120000N without rupturing is used to manufacture the base of the ...

**Science**

Because different mediums have different indexes of refraction. Therefore, when you use Snell's Law: (n1)(sinΘi) = (n2)(sinΘr), depending on the index of refraction of both mediums, the angle of refraction will be different.

**Physics**

What is the maximum mass of a rubber block that can be pulled by a rope whose maximum tension is 3500N? The block is sitting on dry asphalt. (By the way, 1.2 would be used as the coefficient of static friction and 0.8 is the coefficient of kinetic friction for rubber substance...

**Math**

The "-" is from the 6. Because -6(4x+9) is basically (-6)(4x)+(-6)(9) = (-24x)+(-54) = -24x-54. If you are adding a negative value, you are basically subtracting that value.

**Math**

-24x-54 is the simplified answer of that expression.

**Math**

For the work shown above, 4/32 was reduced to 1/8, NOT 4/34

**Math**

2^2/2^5 = 4/34 = 1/8 The answer is C) 1/8

**Geography**

B is correct. NAFTA, ECOWAS, APEC, and MERCOSUR all have to do with money and trade. However, as you most likely know, ISIS is a militant group.

**math**

does the $1450 represent how much interest, or how much money he ended up with in total (including the original amount)? If you mean that $1450 is the interest, then just plug the numbers into the simple interest formula I = PRT

**Geography**

d is correct

**Ms. Sue - 6th Grade Math-Connections Academy**

If one square has a length of 2 feet, then 3 squares in a row is 6 feet long. This means the fountain is 6 feet long. Since its a square, the height is the same as the length. The fountain is 6 feet by 6 feet. Area = Length x Height A = 6 x 6 A = 36 feet squared The answer ...

**Ms. Sue - 6th Grade Math-Connections Academy**

can't really help you without a diagram

**Math**

You need to use a system of equations. Lets say that N equals the number of nickels, and D is the number of dimes. D = 5 x N because there are 5 times as many dimes as nickels .05N + .1D = 57.75 the .05 and .1 represent the value of the coins (N is 5 cents, D is 10) Well, you ...

**math plz its urgent**

I think B is also correct.

**Trigonometric Identities**

Verify/prove the following: (sinA+tanA)/(1+secA) = sinA ______________________________ tanu = 1+sinu-cos^2u/cosu(1+sinu) __________________________________ cotu = (2+cscu/secu)-2cosu ______________________________ tanAsinA/tanA+sinA = tanA-sinA/tanAsinA ...

**Trigonometric Identities**

I'm sorry, I just still don't understand exactly how you even got tan(A+B) = (tanA+tanB)/(1-tanAtanB). What happened to the cotA+cotB, 1-cotAcotB, and 0? If you simplified the original identity, then how did you do that? Because what I did was expand the cot and tan ...

**Trigonometric Identities**

Verify/prove that: (cotA+cotB)/(tanA+tanB)+(1-cotAcotB)/(1-tanAtanB) = 0

**Trigonometric Identities**

Verify/prove that: sinAcosA/1-cosA = sin^2/tanA-sinA

**Math**

Write base-ten number for five hundred seventy-two

**math-story prob**

Let x = number of ultra tickets and y = number of deluxe tickets x + y = 89 3x + 2y = 235 -> -3(x + y = 89) = -3x + -3y = -267 -3x + -3y = -267 + 3x + 2y = 235 ____________________ -y = -32 y = 32 x + y = 89 x + 32 = 89 x = 57 Quinn sold 57 Ultra tickets and 32 deluxe tickets.

**geometry**

thanks

**geometry**

I messed up the question. Mai is ordering an ice cream dessert. She must order a size, a flavor of ice cream, and a topping. There are 5 sizes, 1 flavor, and 2 toppings to choose from. How many different ice cream desserts could she order?

**geometry**

ma is ordering an ice cream dessert. She must order a size, a flavor of ice cream, and a topping. There are sizes, flavor, and toppings to choose from. How many different ice cream desserts could she order?

**Algebra**

(2,-9)(3,2) and (3,-9) find the area of the triangle

**Algebra**

Find the equation in slope intercept form. For the line which is perpendicular to this line 4x + 4y = 3y - 3 and passes through the point (1,-2)

**Algebra**

Two trucks leave a warehouse at the same time. One travels due north at an average speed of 58 miles per hour, and the other travels due south at an average speed of 48 miles per hour. After how many hours will the two trucks be 424 miles apart?

**Trigonometry**

Find (sinϴ + cosϴ) if the terminal side of ϴ passes through (5,2)

**Heat and Heat Transfer**

Two calorimeters each contain 1.4L of water and have a temperature of 26°C In the first calorimeter, you burn a sample of candle wax and determine that 108.2kJ of energy is released. In the second calorimeter, you have to burn 5.4g of candle wax to raise the temperature of...

**Chemistry - Energy Phase Changes**

Calculate the quantity of heat gained or lost in the following change: 0.44 mol of water evaporates at 100 degrees Celsius - So what I did was: 1 mol -> 6.01 kJ 0.44 mol -> x x = 2.64 kJ of energy gained But apparently this is incorrect? Could somebody please explain to ...

**Math - Logarithms**

Could you please explain why lne^2 = 2, e^lne^2 = e^2, e^lin2 = 2, and lne^e = e ? Thank you.

**Math - Logarithms**

Write the following expression as a single logarithm: 4ln2x + ln(6/x) - 2ln2x So I did... 4ln2x + ln(6/x) - 2ln2x = ln2x^4 + ln(6/x) - ln2x^2 = ln16x^4 + ln(6/x) - ln4x^2 = ln16x^(2)(2) + ln(6/x) - ln4x^2 = 2ln16x^2 + ln6 - lnx - ln4x^2 If my calculations so far are correct, ...

**Chemistry - Energy: Phase Changes**

Thank you. Is there an official formula for what you came up with or some sort of rearranged formula?

**Chemistry - Energy: Phase Changes**

An ice cube at 0 degrees Celsius is placed in a pouch and dropped into 30.0g of water in a cup at 45 degrees Celsius. The ice cube melts and the resulting water warms up. The lowest temperature reached by the 30.0g of water in the cup was 20.0 degrees Celsius. What was the ...

**Chemistry - Energy: Phase Changes**

If 13.4 kJ of energy are added to 1.00 kg of ice at 0 degrees Celsius, how much water at 0 degrees Celsius is produced? How much ice is left? The molar heat of melting is 6.01 kJ/mol. So... 6.01 kJ -> 1 mol (6.01 kJ of energy can melt 1 mole of ice) Then... 13.4 kJ -> x...

**Algebra 1**

You're welcome

**Algebra 1**

I think it's actually c, since: y = 1.375x = 1.375(8) = 11 y = 1.375(16) = 22 y = 1.375(24) = 33

**Math**

The answers to questions 1, 2, 3, 6, 7, 8 are most likely correct.

**Logarithmic Function**

No, wait, actually the 2 does not apply to the 2log_2 by itself. Rather, the "2(x+2)" applies to the log. I was so confused, sorry. So I'm going to assume that the answer "2" is correct and the "4" on my answer sheet is incorrect.

**Logarithmic Function**

Thank you. I actaully just figured out that I indeed had miscalculated the equation. It was: y = 2log_2(2) (x+2)-4 Therefore I should solve the "log" part first: 1) y = 2log_2(2) (2+2)-4 2) y = 2 (2+2)-4 3) y = 2 (4)-4 4) y = 8-4 5) y = 4 In other words, the number &...

**Logarithmic Function**

Could you please verify and calculate the following logarithmic equation: y = 2log_2(2)(x+2)-4 , in which x=2. So the equation would become: y = 2log_2(2)(2+2)-4 Solving... y = 2log_2(2)(4)-4 y = 2log_2(8)-4 y = 2(3)-4 y = 6-4 y = 2 So I got y=2, however my answer sheet and my...

**Math**

Use the distance formula, along with the given points: d= √(x2-x1)^2+(y2-y1)^2 d= √(-1+3)^2+(1-2)^2 d= √5

**Heating different volumes of water**

The amount of thermal energy, the number of water particles, or the speed of the particles

**Heating different volumes of water**

Is there a difference between heating 50 mL of water to a given temperature, and heating 100 mL of water to the same given temperature but then removing 50 mL?

**French Expressions**

Does anybody know what the following French expression means: "Je changeais de plan de carrière comme on change de sous-vêtements."

**Physics**

Two light rays, one red and one violet, encounter a glass surface. If the index of refraction of the red light ray = 1.52, the index of refraction of the violet light ray = 1.54, and the angle of incidence = 30 degrees, calculate the angle of refraction of each colour of light...

**Physics**

If a scuba diver is underwater and looks up, he or she will see a round "hole" directly above him or her at the surface of the water. The rest of the surface will look like a mirror. Explain this phenomenon.

**Physics**

Does total internal reflection in an aquarium occur at the separation of the water and the glass or at the boundary of the glass and the water?

**Technolgy**

C b a d just got a 100% on the quick check

**science**

1) The force of gravity on the moon is 1/6 the force of gravity on earth. If you had a 1 kg box of cereal on earth which had a weight of 2.4 N, what would its mass be on the moon? why? 2) what is the volume of a textbook with dimensions 21.3 cm, 27.5 cm, 2.9 cm? please help me...

**Math.**

i don't believe those are right...

**social studies**

asbdd

**Help ? English 10**

protesting injustice

**Math**

required*** Test please excuse my grammar error.

**Math**

Check answer PLEASE!! Kevin wants to calculate the value of the expression below. -17 + 3 Which shows an equivalent way kevin could write this expression? (A.) -(17 + 3) B. -(17 - 3) C. (-3 + 17) D. (-3 - 17) Please help as soon as possible!! I have no one to help me and i don...

**Biology**

Nucleotide

**math**

What is the answer bruh..... You can't just leave a question without a freaking answer dudes

**SCIENCE HELP!**

Me is right! Thanks!

**Law**

yes