# Kristie

Popular questions and responses by Kristie-
## physics

A certain radar installation tracks airplanes by transmitting electromagnetic radiation of wavelength 4.0 cm. a)Find the frequency of this radiation. b)Find the time required for a pulse of radar waves to reach an airplane 4.8 km away and return.

*asked on April 29, 2012* -
## physics

An astronaut on the Moon attaches a small brass ball to a 1.00- m length of string and makes a simple pendulum. She times 15 complete swings in a time of 75.0 seconds. From this measurement she calculates the acceleration due to gravity on the Moon. What

*asked on April 29, 2012* -
## physics

8 1/2 HRS ON THIS MASTERING PHYSICS WOW n 1909, Robert Millikan was the first to find the charge of an electron in his now-famous oil-drop experiment. In that experiment tiny oil drops were sprayed into a uniform electric field between a horizontal pair of

*asked on April 18, 2012* -
## physics

Your friend of mass 80 kg can just barely float in freshwater.Calculate her approximate volume.

*asked on March 27, 2012* -
## physics

Electronic types neglect the force of gravity on electrons.To see why, compute the force of Earth's gravity on an electron and compare it with the force exerted on the electron by an electric field of magnitude 6000 V/m (a relatively small field). The mass

*asked on April 18, 2012* -
## Physics

Consider the equation v = 1/4zxt^2. The dimensions of the variables v, x, and t are [L]/[T], [L], and [T], respectively. The numerical factor 4 is dimensionless. What must be the dimensions of the variable z, such that both sides of the equation have the

*asked on September 2, 2012* -
## physics

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. Find the

*asked on March 28, 2012* -
## physics

1909, Robert Millikan was the first to find the charge of an electron in his now-famous oil-drop experiment. In that experiment tiny oil drops were sprayed into a uniform electric field between a horizontal pair of oppositely charged plates. The drops were

*asked on April 20, 2012* -
## physics

In periods of peak demand, power companies lower their voltage. This saves them power (and saves you money!). To see the effect, consider a 1200- W coffeemaker that draws 10 A when connected to 120 V. Suppose the voltage is lowered by 13 % to 104

*asked on April 19, 2012* -
## physics

In a 25 degree C room, hot coffee in a vacuum flask cools from 72 degree C to 54 degree in 8 hours.Find its temperature after another 8 hours.

*asked on March 31, 2012* -
## Physics

A 67 kg hiker climbs to the top of a 3700 m-high mountain. The climb is made in 5.5 h starting at an elevation of 2800 m. Calculate assuming the body is 16% efficient, what rate of energy input was required.

*asked on February 28, 2011* -
## physics

A 56 kg bungee jumper jumps from a bridge. She is tied to a bungee cord whose unstretched length is 11 m, and falls a total of 38 m. Calculate the spring stiffness constant k of the bungee cord, assuming Hooke's law applies. Calculate the maximum

*asked on February 28, 2011* -
## physics

Estimate the buoyant force that air exerts on you. (To do this, you can estimate your volume by knowing your weight and by assuming that your weight density is a bit less than that of water.) Assume that your weight is a about 1000 N, for example.

*asked on March 28, 2012* -
## physics

Is it true that all radio waves are faster than all sound waves—no exceptions? A) False always.B) True, in most common cases.C) False in some cases.D) True in all cases.

*asked on April 29, 2012* -
## physics

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. I got the

*asked on March 31, 2012* -
## physics

A mountain-climber friend with a mass of 82 kg ponders the idea of attaching a helium-filled balloon to himself to effectively reduce his weight by 25% when he climbs. He wonders what the approximate size of such a balloon would be. Hearing of your physics

*asked on March 28, 2012* -
## physics

Suppose that you balance a 6kg ball on the tip of your finger, which has an area of 1 cm^2 Find the pressure on your finger.

*asked on March 27, 2012* -
## physics

The finding that light in free space has one speed, and one speed only, is consistent with ____________________. A) the conservation of energy as shown by Maxwell.B) general relativity.C) Newton's laws of motion.D) electromagnetic induction. My book tells

*asked on April 28, 2012* -
## physics

On a perfect fall day, you are hovering at low altitude in a hot-air balloon, accelerated neither upward nor downward. The total weight of the balloon, including its load and the hot air in it, is 24000 N. Find the weight of the displaced air. I got the

*asked on April 1, 2012* -
## algebra

The population of a particular country was 29 million in 1985; in 1997, it was 38 million. The exponential growth function describes the population of this country t years after 1985. Use the fact that 12 years after 1985 the population increased by 9

*asked on February 29, 2016* -
## Chemistry

How many kilocalories of heat are released when 125 g of water cools from 100.0oC to 19.5oC?

*asked on June 20, 2013* -
## math

And armored truck left a federal bank at noon when a shipping error was discovered an agent was sent by helicopter to overtake the truck the helicopter left at 1:48 PM and flew at an average speed of 170 km/h. If the truck was overtaken at 3:24 PM what was

*asked on August 12, 2015* -
## chemistry

a rectangular block of the element barium is 5.00cm long , 3.00cm wide and 1.00cm high and it weighs 52.5g. what is the density of the element barium?

*asked on September 27, 2011* -
## statistics

if 1 adult male is randomly selected and is assumed to have 20 lb of carry on baggage, find the probabilty that his total is greater than 195 lb

*asked on November 9, 2011* -
## physics

What are the temperatures for freezing water and boiling water on the Kelvin temperature scale? a)273K for freezing water; 373K for boiling water b)0K for freezing water; 100K for boiling water c)32K for freezing water; 212K for boiling water

*asked on March 29, 2012* -
## physics

A 6.2kg piece of metal displaces 0.80 L of water when submerged.Find its density.

*asked on March 27, 2012* -
## physics

The weight of the atmosphere above 1 m^2 of Earth's surface is about 100,000 N. Density, of course, becomes less with altitude. But suppose the density of air were a constant 1.2 kg/m/s^3. Calculate where the top of the atmosphere would be.

*asked on March 28, 2012* -
## principles of physics

Calculate the force of gravity between Earth and the Sun (the Sun's mass = 2.0×10^30 kg; average Earth-Sun distance = 1.5×10^11 m).

*asked on March 9, 2012* -
## math

how would you solve for y in this problem: x=(y^2+3y)^(1/3) would it equal: y= x^3/y - 3 ? and what about this problem: x= 1/[(y^2+3y-5)^3] would it equal: y = y/x + 5/y - 3? I would appreciate your help very much! Your equation is correct but it does not

*asked on June 27, 2006* -
## physics

The feature that our eyes are most sensitive to seeing is which of the following? A) edges or boundaries.B) images that fall on the blind spot.C) gray areas.D) anything at the periphery.E) all light of moderate intensity.

*asked on April 29, 2012* -
## principles of physics

Calculate the force of gravity between a newborn baby (mass = 2.6 kg) and the planet Mars (mass = 6.4 * 10^23kg) when Mars is at its closest to Earth (distance = 5.6 * 10^10m).

*asked on March 9, 2012* -
## physics

A 297-kg motorcycle is accelerating up along a ramp that is inclined 25.9° above the horizontal. The propulsion force pushing the motorcycle up the ramp is 3156 N, and air resistance produces a force of 300 N that opposes the motion. Find the magnitude of

*asked on September 25, 2012* -
## physics

What would be the final temperature of a mixture of 50 g of 15 degrees C water and 50 g of 40 degrees C water?

*asked on March 29, 2012* -
## Physics

In a double-slit experiment, the fourth-order maximum for wavelength of 450 nm occurs at an angle theta = 90. Thus it is on the verge of being eliminated from the pattern because theta cannot exceed 90. (a) What range of wavelengths in the visible range

*asked on March 13, 2016* -
## Math 7th grade

A recipe serves 12 people and requires 1/5 cup of eggs. If you wanted to make the same recipe to serve 4 people, how many cups of eggs would you need? Show your work.

*asked on February 29, 2016* -
## physics

Rank the speed of sound through the following from greatest to least:A. HeliumB. Benzene C. Mercury

*asked on April 29, 2012* -
## physics

Touch a 5000-V charged balloon and you're not harmed because, although the energy/charge ratio is high, there is ____________________. A) very little conduction of electricity.B) very little energy on the balloon.C) no way this large amount of energy can

*asked on April 10, 2012* -
## principles of physics

my last one!! Calculate the force of gravity between a newborn baby of mass 2.9 kg and the obstetrician of mass 100 kg, who is 0.58 m from the baby.

*asked on March 9, 2012* -
## college

Translate to an equation: r $2 roses and t $2.50 tulips total $30 graph the equation and use the graph to determie three different combinations of roses and tulips that total $30.

*asked on December 15, 2010* -
## medical

which one of the following statements is an example of hearsay? a)i saw the doctor administer the injection.b)i checked the patients blood pressure three times.c)the report said the patient died on january 15.d)the report was on my desk when i arrived for

*asked on August 14, 2010* -
## physics

Consider a wave that travels a distance of 3 meters in 1 second with a frequency of 2 hertz. What is its amplitude? A) 4 meters.B) 2 meters.C) Not enough information is given.D) 3 meters.E) 1 meter.

*asked on April 29, 2012* -
## physics

Light has a maximum constant speed in which of the following? A) water.B) red glass.C) the upper atmosphere.D) clear glass.E) between the atoms in glass, water, or the atmosphere. IS THIS C THE UPPER ATMOSPHERE?

*asked on April 29, 2012* -
## physics

The number of electrons that move about the nucleus of an electrically neutral atom is the same as the number of ____________________. A) protons in the nucleus.B) quarks in the nucleus.C) protons + neutrons in the nucleus.D) neutrons in the nucleus.E)

*asked on April 13, 2012* -
## MATH

I need to simply this equation, but I got stuck. h/(4-sqrt(16+h)) = y First, I multiplied (4+sqrt(16+h)/(4+sqrt(16+h) to both sides, and I ended up with h(4+sqrt(16+h)/-h. Is this correct? (I tried to graph both equations to see if I would get the same

*asked on August 8, 2006* -
## principles of physics

Blood pressure is normally greater in your ____________________. A) arms.B) legs.C) head.D) feet.E) All the same

*asked on March 19, 2012* -
## MATH HELPPPP

in the diagram below,

*asked on February 27, 2012* -
## physics

To say that charge is conserved is to say that charge ____________________. A) is transferred, but never created or destroyed.B) is stored and never lost.C) None of the above.D) remains the same, whatever occurs physically.E) All of the above.

*asked on April 13, 2012* -
## physics

Which of these are correct for an electric field? A) It's a vector quantity, and can be cancelled.B) Three of three are correct.C) It stores electric energy.D) Two of three are correct.E) It's the altered space surrounding electric charge.

*asked on April 10, 2012* -
## physics

Consider an airplane with a total wing surface of 90 m^2. At a certain speed the difference in air pressure below and above the wings is 4.2% of atmospheric pressure. Find the lift on the airplane.

*asked on March 28, 2012* -
## inverse

the direction was to find f^(-1)x. f(x) = x^2+2x+1, x >= -1 as a final answer, I got: f^(-1)x = sqrt(x) - 1, x >= 0 is this right? I don't understand the restriction rules. It is right. If originally x>=-1, that puts f(x) >=0, and in the inverse function,

*asked on July 17, 2006* -
## physics

Sound waves have which of these properties? A) Reflection.B) All of these.C) Refraction.D) Interference.E) Capable of producing beats.

*asked on April 30, 2012* -
## statistics

Suppose that weights of 5th grade elementary boys are normally distributed with mean µ =90 lbs and variance ó2 = 4 lbs. Find the weight that corresponds to Q3 and interpret this measure of position.

*asked on November 28, 2011* -
## physics

Frequency and period are related, in that they are which of the following?A) inverses of each other.B) None of these.C) both on the same wavelength.D) directly proportional to each other.E) two expressions for much the same thing.

*asked on April 29, 2012* -
## physics

Frequency and period are related, in that they are which of the following?A) inverses of each other.B) None of these.C) both on the same wavelength.D) directly proportional to each other.E) two expressions for much the same thing.

*asked on April 29, 2012* -
## physics

In periods of peak demand, power companies lower their voltage. This saves them power (and saves you money!). To see the effect, consider a 1200- W coffeemaker that draws 10 A when connected to 120 V. Suppose the voltage is lowered by 13 % to 104

*asked on April 20, 2012* -
## geometry

Given: ÚA≅ÚBDE; AB x DE = AD x BD Prove: AB x CD = AD x BC

*asked on December 16, 2010* -
## math!

about finding the inverse of y=(2x+1)/(x+3). should you multiply (x+3) on both sides and get y(x+3)=2x+1? then what would be your next step? This one is a little tricky because we we have a rational function. What we want to end up with is x(y) To do this

*asked on July 20, 2006* -
## physics

Given that the power consumed by a device is 1000 W operating on a 70-V line, calculate the amount of current it draws.

*asked on April 18, 2012* -
## physics

The difference between energy radiated from the sun and energy radiated from the Earth has to do with ____________________. A) Neither of these.B) Both of these.C) radiation frequencies.D) the amounts of radiant energy.

*asked on March 25, 2012* -
## physics

Which of the following 1-gram blobs of water has the least surface area? A) All have about the same surface area.B) A spherical blob.C) A blob stretched into a thin film.D) A pancake shaped blob.E) An ellipsoid-shaped blob.

*asked on March 19, 2012* -
## pathophysiology

Regarding lipoproteins: A) HDL promotes coronary artery disease B) The higher the ratio of lipid to protein, the higher the density C) LDL proportionately has more protein to lipids D) LDL is promotes coronary artery disease E) none are true

*asked on July 4, 2012* -
## physics

A sonic boom is produced by an aircraft when it does which of the following? A) flies faster than sound continuously.B) None of these.C) All of these.D) first exceeds the speed of sound and breaks the sound barrier.E) pulls out of a subsonic dive.

*asked on April 29, 2012* -
## Math

in the diagram below,

*asked on February 27, 2012* -
## math

I have to find an exact solutions on the interval [0,pi) for both of these problems-- 1) 2sin2x = sqrtx and 2) 1-2sqrt2 sinxcosx = 0 I know this much: 1) sin2x = (sqrt x)/2 = 2sinxcosx = (sqrt x)/2 What do I need to do next? 2) 1/(2 sqrt2) = sinxcosx =

*asked on August 1, 2006* -
## math

how would you solve for y in this problem: x=(y^2+3y)^(1/3) I got: y= x^3/y - 3 ? and for this problem: x= 1/[(y^2+3y-5)^3] I got: y = y/x + 5/y - 3? However, I do not know how to solve for y explicitly. I don't think quadratic formula would work in these

*asked on July 20, 2006* -
## domain

How do you find the domain of log(x^2-4)? and how about this one? e^(3x+4)? Please help me! Well kristie, you might recognize log(x^2-4) = log((x-2)(x+2)) and then use a property of logs to see it as a sum, i.e., log(ab)=log(a)+log(b). You are then

*asked on July 17, 2006* -
## math

how would you solve for y in this problem: ln(y-1)-ln2 = x +lnx ln(y-1)-ln2 = x +lnx Solve for y... ln[(y-1)/2]]=x + lnx take the antilog of each side (y-1)/2= e^(x+lnx) solve for y.

*asked on July 11, 2006* -
## math

how would you simplify this equation: y = (x+3)/[(4-sqrt(16+h))] please help me! you have three variables. I am not certain "simplify" is an appropriate term here. ohhhh it was my mistake. I meant: y = h/[(4-sqrt(16+h))] y = h/[(4-sqrt(16+h))] rationalize

*asked on June 30, 2006* -
## physics

If you double the frequency of sound, you also double which of the following? A) All of these.B) None of these.C) wavelength.D) amplitude.E) speed.

*asked on April 30, 2012* -
## physics

Charge polarization is normally produced by ____________________. A) nuclear interactions.B) contact.C) induction.D) friction.E) electrostatic means.

*asked on April 10, 2012* -
## physics

The temperature at the bottom of Lake Tahoe in the Sierra Nevada Mountains of California is 4°C year round. In which country is water at the bottom of lakes normally higher than this? A) Russia.B) Great Britain.C) New Zealand.D) Tibet.E) Singapore.

*asked on March 25, 2012* -
## MATH

(x^2-2x+4)/ ((x-2)(x^2+4)) = y can this equation be simplified farther? I don't see an easy simplification.

*asked on August 8, 2006* -
## math

please help me simplify (x^3+8)/(x^4-16). thanks. The denominator is cleary the differerence of two squares (X^2-4)(x^2+4). That can again be factored to (x+2)(x-2)(x^2+4). The numerator can be factored using the trinomial simplification..

*asked on July 25, 2006* -
## interval

Find the exact solutions on the interval [0,pi]. 2sin2x = sqrt(x) Please help me! kristie, this problem is somewhere between a calculus problem and an algebra one. I'm not sure what you're taking. If you see that the eq. is = to 4(sin2x)^2=x , then you

*asked on July 13, 2006* -
## physics

Beats in sound are the result of which of the follwing wave? A) resonance.B) refraction.C) reflections.D) amplitude changes.E) interference

*asked on April 29, 2012* -
## physics

The ocean level rises when global temperature rises, due to ____________________. A) Both of these.B) Neither of these.C) melting of ice caps at the poles.D) thermal expansion of water

*asked on March 25, 2012* -
## physics

The ocean level rises when global temperature rises, due to ____________________. A) Both of these.B) Neither of these.C) melting of ice caps at the poles.D) thermal expansion of water.

*asked on March 24, 2012* -
## college

use the five steps for problem solving. the average of two test scores is 79. if one test score is eleven less than the other, what are the two test scores?

*asked on December 8, 2010* -
## Chemistry

Why is it important to identify the limiting reactant in stoichiometry?

*asked on March 5, 2013* -
## HUMAN DISEASES

WHAT IS THE Highly sensitive blood test and marker for myocardial infarction CALLED

*asked on July 1, 2012* -
## physics

If you double the frequency of sound, you also double which of the following?A) All of these.B) None of these.C) wavelength.D) amplitude.E) speed.

*asked on April 30, 2012* -
## physics

Charge polarization is normally produced by ____________________. A) nuclear interactions.B) contact.C) induction.D) friction.E) electrostatic means.

*asked on April 13, 2012* -
## physics

1. Temperature is distinguished from heat when we note that whereas temperature is ____________________. A) None of these.B) measured in degrees, heat is measured in units of energy.C) a measure of average translational kinetic energy per molecule, heat is

*asked on March 25, 2012* -
## physics

Temperature is distinguished from heat when we note that whereas temperature is ____________________. A) None of these.B) measured in degrees, heat is measured in units of energy.C) a measure of average translational kinetic energy per molecule, heat is

*asked on March 24, 2012* -
## MATH

in the diagram below,

*asked on February 27, 2012* -
## uop

Benjamin O'Henry has owned and operated O'Henry's Data Services since its beginning ten years ago. From all appearances, the business has prospered. In the past few years, you have become friends with O'Henry and his wife. Recently, O'Henry mentioned that

*asked on May 16, 2008* -
## math

Could you show me step by step how to find the inverse of this problem: log with base of 2 (x+1) Thanks! It is not clear what the problem is. You are given a function of x. Let's calli it y. Are you trying to come up with an equation for x in terms of y?

*asked on July 21, 2006* -
## math

how would you simplify y= (x^5-32)/(x-2)? I know that it would equal (x^5-2^5)/(x-2), but what's the next step? It wouldn't be just (x^4-2^4), would it? kristie, in general I think you can prove (x-a)|(x^n - a^n); read (x-a) divides the expression on the

*asked on July 18, 2006* -
## inverse

my question was: find f^-1 (x). (this is asking me to find the inverse) f(x) = -(x-2)^2, x > and you answered: If f(x)=-(x-2)^2 x

*asked on July 13, 2006* -
## math 107

Use the following diagram of a flowerbed of petunias to answer the following questions. This diagram is a rectangle with ½ a circle on each end. The circle diameter is 22 feet, while the length of the rectangle is 60 feet. If you draw an X in the middle

*asked on February 23, 2015* -
## HUMAN DISEASES

Regarding lipoproteins: A) HDL promotes coronary artery disease B) The higher the ratio of lipid to protein, the higher the density C) LDL proportionately has more protein to lipids D) LDL is promotes coronary artery disease E) none are true

*asked on July 1, 2012* -
## physics

Electric potential is measured in units of ____________________. A) watts.B) joules per coulomb, or volts.C) joules.D) ohms.E) amperes.

*asked on April 10, 2012* -
## principles of physics

For which of these will the buoyant force be the same as its weight when placed in water? A) A match stick.B) All of these.C) A small rock.D) None of these.E) A nail.

*asked on March 19, 2012* -
## chem

a rectangular block of the element barium is 5.00cm long , 3.00cm wide and 1.00cm high and it weighs 52.5g. what is the density of the element barium?

*asked on September 27, 2011* -
## Algebra

Solve 16 - 2(8w-7)= 3w - 18(2-w)

*asked on December 17, 2010* -
## Geometry

Can you help me solve 12 degrees, 15 minutes, and 22 seconds minus 10 degrees 16 minutes and 26 seconds?

*asked on February 4, 2010* -
## Physical Science

Is the speed of light directly proportional to the distance traveled?

*asked on May 12, 2009* -
## Math

Define a parallelogram

*asked on March 23, 2009* -
## math

is log (x/y)= log (x-y)

*asked on December 10, 2008* -
## inverse

find f^-1 (x). (this is asking me to find the inverse) f(x) = -(x-2)^2, x If f(x)=-(x-2)^2 x

*asked on July 11, 2006*

## Pages

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