# Posts by David

Total # Posts: 2,261

**Physics**

You are traveling on an airplane. The velocity of the plane with respect to the air is 110.0 m/s due east. The velocity of the air with respect to the ground is 39.0 m/s at an angle of 30° west of due north. 1) What is the speed of the plane with respect to the ground? 2) ...

**algebra**

(3,0),0,-4).solve for length, standard form.thank you

**algebra**

(3,0),0,-4).solve for length, standard form.

**algebra**

(3,0),0,-4).solve for the following :

**Health**

The answer is K ;)

**Math**

Find the half-life (in hours) of a radioactive substance that is reduced by 10 percent in 5 hours.

**physics**

A red ball is thrown down with an initial speed of 1.0 m/s from a height of 27.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.5 m/s, from a height of 0.7 meters above the ground. The force of ...

**Physics**

A tortoise and hare start from rest and have a race. As the race begins, both accelerate forward. The hare accelerates uniformly at a rate of 0.8 m/s2 for 4.4 seconds. It then continues at a constant speed for 13.5 seconds, before getting tired and slowing down with constant ...

**physics with 6 questions**

Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 3.3 m/s2 for 3.9 seconds. It then continues at a constant speed for 13.7 seconds, before applying the brakes such that the ...

**Physic**

Type A nerve fibers in humans can conduct nerve impulses at speeds up to 139.8 m/s. How fast is this in mph? This is a question from my physic homework. I have tried converting 139.8 m/s to mile then to hrs and i got .000241 mph. When I input it it said this is not correct. ...

**physics**

A rolling ball moves from x1 = 3.2 cm to x2 = -4.2 cm during the time from t1 = 3.8 s to t2 = 6.1 s. What is its average velocity?

**math**

Estimate. 247 * 974 a. Write your estimate as a number sentence: ________________ b. How I estimated : ________________________________

**Stats**

Question 3 Investment analysts generally believe the interest rate on bonds is inversely related to the prime interest rate for loans; that is, bonds perform well when lending rates are down and perform poorly when interest rates are up. Can the bond rate be predicted by the ...

**Stats**

This assignment requires you to use Excel. In question 1, you will use the charting features. In questions 2 and 3, use the regression tool from the analysis toolpack. There is no template for this assignment. Make sure you explain your answers and provide the regression ...

**Math**

Joelle earns her regular pay of 7.50 per hour for up to 40 hours a week. for each hour over 40 hours of work in a week, joelle is paid 1.5 times her regular pay. how much does joelle earn for a week in which she works 42 hours?

**psychology**

After watching golf on TV several times with her father, 7-year-old Michelle learned how to swing a club even before she actually had one in her hands. What kind of learning took place?

**health**

HAHAHA ME TOO THIS ANSWERS ARE REALLY HELPFUL THANKS

**Physics**

How long would it take a car engine, say 500 pounds of iron, to cool from 1,200 degrees F (exauhst manifold temp) to air ambient temp. of 75 degrees F.

**Physic**

What is the source of the sun's energy?

**Stastistic**

Finde the mean , variance , standard deviation N-127, P=0.66

**math**

Frank's cell phone package costs $20 per month and an additional $0.05 per text. Josie pays $15 per month and $0.10 per minute. Determine the linear system that could be used to find out when their monthly bills would be the same.

**MATH**

Find the amount of interest and the monthly payment for the loan. Purchase a living room set for $3,800 at 12% add-on interest for 3 years.

**statistics**

Surgery vs. placebo for the knee pain: Refer to Example 10. Is Arthroscopic Surgery Better than Placebo? Here we show MINITAB output comparing mean knee pain scores for the placebo (group 1) to debridement arthroscopic surgery (group 2). a) State and interpret the result of ...

**Physic**

What are some sources of energy that are available to heat the interiors of planets?

**science**

2 WAYS TO DETERMINE THE INTERIOR ARE GRAVITY, AND SEISMOLOGY.

**Science**

How can we use Kepler's laws or Newton's laws to learn about these objects?

**Astronomy**

How were the different objects in the solar system discovered? What are the properties of the ice giants?

**Physic**

alive

**calculus**

How do I take the partial derivative of P with respect to r of the following: D ~ P = ‡”(t=1 to T)[t ~ (CF)_t/(1+r)^t ]

**math**

5x-y=22 x+9y=32

**Physics?**

In Rutherford's scattering experiments, alpha particles (charge = +2e) were fired at a gold foil. Consider an alpha particle, very far from the gold foil, with an initial kinetic energy of 2.0 MeV heading directly for a gold atom (charge +79e). The alpha particle will ...

**math**

5040

**Alg/Trig**

(x-2)^2 + (y-3)^2 = 4.5^2

**math ( pre algebra )**

B. H

**math**

nonsense. let the three batteries by A,B,C then A = 2B 3A = C A + B + C = 54 so A = 12 B = 6 C = 36

**math**

How do I take the partial derivative of P with respect to r of the following: D × P = ∑(t=1 to T)[t × (CF)_t/(1+r)^t ]

**Algebra 2**

Thanks Ms Sue its my daughters problem ,my responce was maybe the wording might be asking "what investment " might be what amounts in what types of investments would yield the $4ooo. Or it might be just be about the math and analizing it. Either way ,thank you

**Algebra 2**

As a graduation present, you want to gift your son a trip to Disney World. Presently beginning his second semester as a high school junior, you hope you have enough time to save $4,000 to support much of the trips expenses for your child and two of his closest friends. Rather ...

**english/grammar**

I need help editing errors in parallelism in the following sentence: Is it true that Superman could leap tall buildings, run faster than a locomotive, and that bullets would bounce off his skin?

**105 personal dimension of education**

my classes start 5-29-`12, can I get a better idea of whats ahead of me(course description)or what it consist of. Thank you

**grammar**

ops whats the first one

**grammar**

Whats the last one?

**physics**

or I've kept up with my homework and work this whole year except that our teacher just randomly decided to give us a ton of homework this weekend, and I have done all I can do. All of my friends are in the physics 1 class while this is physics 2 so no I cannot have answers...

**physics**

Hi, my teacher doesn't teach us too well and we have a few packets to hand in for tomorrow that I really don't understand much of. If someone could give me the answers to all of the problems on the first link if you search "the electrical energy converted to ...

**Geometry word problem**

A rectangular pond is 10m longer than it is wide. A walk 2m wide surrounds the pond. Find the dimensions of the pond if the area of the walk is 216m2

**Geometry**

A rectangualar playground is 4 meters longer than it is wide. If the length is increased by 5m, and the width decreased b y 1 m, the area is increased by 15m SQUARED(15M2).Find the original dimensions of the playground.

**Math**

How do i solve 2x+y > -3? And how do i graph it. This is Linear inequalities.

**phisycal sciences**

Which of the following properties did Rutherford use in his experiment? A. the negative charge of the alpha particles and the random distribution of protons B. the negative charge of the alpha particles and the positive charge of the gold foil C. the positive charge of the ...

**Mathematics**

Two numbers have thousandths other than zero. Could the difference of these numbers be 5.3? Explain.

**algebra 2**

Write an equation for a parabola with vertex at (3,- 6) and focus at (3,- 4).

**chemistry**

Is beta particles the answer?

**chemistry**

Which radioactive emanations have a charge of -1? beta particles alpha particles gamma rays neutrons

**Algebra**

-4x+1-2(x-1)= -4(x-4)

**algebra**

Write an equation of the hyperbola with foci (0, ) and (0, 2) and vertices of (0, ) and (0, 1).

**spanish**

Escribe el cual (la cual, los cuales, las cuales) o lo cual en el espacio. Nos invitaron a cenar con ellos, ____ fue una buena idea.

**spanish**

¿Cuál frase es correcta? El hijo del maestro, quien estuvo en mi clase, es muy inteligente. El hijo del maestro, a quien estuvo en mi clase, es muy inteligente.

**algebra**

When you spend $1 at the grocery store, the store doesn’t keep all of your money as profit. Some of it is reinvested in the economy when the grocery store buys more merchandise from suppliers. In turn, the suppliers don’t keep all of that money as profit, either; ...

**Finance**

Calculate the weighted cost of equity for a firm with the following characteristics: (a) Last Dividend--$5.00, (b) Growth Rate—6%, (c) Price of Stock--$125.00 and (d) Weight of Equity Capital—40%

**English**

Help me to write these answer question, Write an essay that illustrate the saying every cloud has a silver lining in 340 words

**American Lit.**

What is Fundamentalist-Modernist Controversy.? Is this one whole topic or more than one.?

**computer programming**

Make an Maplet that does the simple calculator funtions as addition, subtraction, multiplication, division, factorial, sin(), cos(), tan(). (using maplet in maplesoft)

**physics**

a one meter chain that weights one newton sits on a flat horizontal table that is one meter from the floor. the coefficient of friction between the chain and the table is 0.15. how much of the chain can dangle off the table until the chain pulls itself onto the floor? if it ...

**College Algebra**

log5 (x+2)+log5(x-2)=3

**algebra**

2(2x+5)-7<12 2(2(-5)+5)-7<12 2(-10+5)-7<12 2(-5)-7<12 -10-7<12 -17<12

**geometry**

A circle of radius r is centered at the origin and a rectangle is inscribed. The area of the rectangle as a function is given by what? Can you also explain the processes behind finding the answer it helps me understand.

**Environmental Science**

7 is D 10 is probably B because mosses are the first thing to grow naturally after the destruction of an environment like building a building 21 is D the y all effect marine ecosystems and are caused by humans 27 is D

**Chemistry**

Calculate the Concentration of Ni2+ in a soltion which prepared as mixing 50.0ml 0.0300 M Ni2+ and 50.0mlml 0.0500 M EDTA at pH= 3 At pH=3 , α4= 2.5x10-11 KNiY=4.2x1018

**Chemistry**

calculate the the pH of a buffer solution containing 0.246 M NH3 and 0.0954 M NH4Cl (for NH3 Kb = 1.74x 10-5)

**Chemistry**

what mass of AgBr is formed when a solution containing 3.45 g of KBr is mixed with a solution containing 7.28 g AgNO3?

**chemistry**

You have a 1 L container of a gas O 2 at 20°C and 1 atm. Subtracting the weight of the container, what is the mass of the gas?

**physics**

A truck covers m in 8 s while smoothly slowing down to a final speed of 2.8 m/s. (a) Find its initial speed. (b) Find its acceleration.

**Chemistry**

How many grams of water are formed when 250 mL of 2.0 M Mg(OH)2 are neutralized by a solution of HCL ?

**Chemistry**

How many mL of 3.0 M HCL are required to neutralize 250 mL of 2.0 M MgCL2 ?

**MaTh AlgeBRA**

Do synthetic division or long division Domain is all reals except x=1 because it gives you a 0 denominator.

**Calculus**

Let (3,1,-2) = C A+B=C B=C-A B=C+(-A) Do the addition component by component.

**Chemistry**

Both compounds are soluble, thus you have a double replacement reaction. Do stochiometry with the balanced reaction to find the concentrations.

**Physics**

Because of the symmetry in the path of a projectile, it will return to your hand with a speed of 40 m/s downward. Its total displacement is 0 since it returns to starting position. To find the distance traveled, multiply the height it reaches by 2. Find the height using ...

**Physics**

Assuming the angle of the throw was perfectly horizontal, x=v0*t=10*4=40m

**physics**

x=Vo*t since no forces act on the car in the x direction. Solve for t, t = x/v0^2 y=Vo*t+at^2/2 in this case, y = h, Vo in the y direction is 0, a = -g and use the relationship from before. Substitute solve for Vo^2 and your all done

**math**

x+x+3=57

**Algebra II**

x1/y1=x2/y2

**conics**

slope of PO= y/x slope of PN = y/(x-12) For segments to be perpendicular their slopes must be negative recipricols Thus, -x/y=y/(x-12) y^2+x(x-12)=0 Distribute the x, complete the square, and then you'll have the equation of a circle.

**math**

Draw a quadrangle below.Measure the sides to the nearest 1/2 inch.Write the length next to each side.Find the perimeter.

**physics**

Howstuffworks has a pretty thorough yet comprehensible explanation. I'd check that out.

**CHEM**

if something has a pH of 3.72 its not a base... did you mean pOH?

**physics**

T is period so you have frequency and period backwards

**physics**

use the formula T = 2*pi*sqrt(L/g) make sure you use SI units.

**physics**

Use the relationships 1 watt = 1 Joule / second E = mc^2 E = energy, m = mass, c = speed of light (3*10^8 m/s)

**physics**

you need to know that relationship that in that form, w = 2*pi*frequency thus w = 2*pi*525 2)cycles per 1 minute = 60 seconds *frequency = 60 * 535

**math**

13*3=39

**math**

6*10 + 10*(1/2) = 65

**trig**

Cosine is 0 at pi/2 3pi/4*t=pi/2 t=2/3

**physics**

w = 2*pi*period

**physics**

nevermind I thought it said that it began at its highest point. Since they didn't specify any initial conditions you're free to use either sin or cosine with no phase shift.

**physics**

It doesn't make a difference as long as your value for when t = 0 is correct since sin is just cosine phase shifted by pi/2. Cosine is probably easier in this case because then you wont need to do a shift.

**physics**

Period = time per cycle = 15 seconds frequency = 1 / period = 1/15 hz amplitude= 3 ft because its actually the distance from the center to each side. from there just put it into standard form.

**Chemistry**

It depends on the indicator. At the equivalence point, hypothetically they are equal. Most indicators however do not change color at exactly 7 and thus pH of the endpoint determines the concentrations of H+ and OH-

**Physics**

If the bus is moving with constant velocity, there's no net force on the bus, and thus you don't need to compensate for the bus's motion. If the bus is moving forward with constant acceleration, there will be a force pushing the bus forward, however from inertia ...

**math**

total time = 4 hours + 3 hours = 7 hours. Avg speed = total distance / total time Avg speed = 40 * 2 / 7 = 80/7 km/h

**math**

total distance = 526 + 5 * 70 avg speed = total distance / 12 min