# Danny

Newest questions and responses by Danny-
## Math

Gabriella’s travel shampoo bottle holds 1/2 cup of shampoo before leaving on vacation she filled the bottle to the top with 1/8 cup of shampoo how much shampoo was already in the bottle?

*asked on September 10, 2018* -
## Optics

The famous Chinese magician Foo Ling Yu performs a classic magic trick using a concave mirror with a focal length of 1.6 m. Foo uses the mirror to produce an image of a light bulb that is the same size as the light bulb itself and is at the same location.

*asked on June 6, 2018* -
## Trig

How would you show that sin(x+pi)=-sin x? I’m not sure how to start so if someone can tell me how to start it I should be able to do the rest.

*asked on May 28, 2018* -
## Trig

the graph of an inverse trigonometric function passes through the point (1,pi/2). which of the following could be the equation of the function Y=Cos^-1 x Y=cot^-1 x Y=Sin^-1 x Y=Tan^-1 x

*asked on March 7, 2018* -
## physics

calculate the horizontal force that must be applied to produce an acceleration of 72 m/s^2 for a 0.034 kg punk on a friction less air table

*asked on December 1, 2017* -
## Biology

Why can viruses of the family of the Poxviridae be genetically modified more easily than viruses of most other viral families? A. Because their genome is smaller. B. Because their genome is made of DNA. C. Because their genome mutates more slowly. D.

*asked on October 2, 2017* -
## Math

It is a prime number. The number is less than 30,greater than 20. The sum of thedigit is less than 10. What is the mystery number

*asked on May 8, 2017* -
## English Grammar 5th grade

Answers for suffixes colorful, late, northern, troubled, straight, friendly, dry, safe, useful, flat, willing, early, hungry, blue, worst, sad. Thanks! For Helping me!

*asked on April 28, 2017* -
## Physical Science

Answer the following in terms of volume, temperature, and/pressure. As a syringe plunger is pushed down, why does the marshmallow inside the syringe get squished even though the plungerr never touched it? What law does this demonstrate?

*asked on April 25, 2017* -
## ELA

In Sitton Spelling and Word Skills Practice Book, What is the answers antonyms: after less south remember against tall unimportant import evening backward unusual disorganized rebel periphery temporary latter Synonyms: change assist deficit revive

*asked on April 19, 2017* -
## Biology

1. How do mutations play into the fitness of an organism? 2. Describe how variation, selection and time fuel the process of evolution.

*asked on April 10, 2017* -
## Biology

1. How do mutations play into the fitness of an organism? 2. Describe how variation, selection and time fuel the process of evolution.

*asked on April 9, 2017* -
## alg 2 first final study guide

f (x) =2X^3 + 2x^2 - 3x + 2 please help me set up to find all the real number zeros of the function

*asked on December 10, 2016* -
## Math

Jessica played on the school chess team last year. She won 65% of the games She played. If She won 13 games, How many did She playi?

*asked on November 18, 2016* -
## Calculus - Word Problems

Suppose a spherical snowball is melting at a constant rate of 0.20in per hour. How fast is the volume changing when the radius is 10in?

*asked on November 14, 2016* -
## Calculus - Optimization

The post office ships a package using large package rates if the sum of the length of the longest side and the girth (distance around the package perpendicular to its length) is greater than 84in and less than or equal to 108in. Suppose you need to ship a

*asked on November 14, 2016* -
## Calculus

The post office ships a package using large package rates if the sum of the length of the longest side and the girth (distance around the package perpendicular to its length) is greater than 84in and less than or equal to 108in. Suppose you need to ship a

*asked on November 14, 2016* -
## Chemistry

Consider the following reaction. 2Fe2O3 --> 4Fe+3O2 Hrxn=+824.2 The Formation of 21.0 of Fe results in 1)the release of 77.5 kJ of heat. 2)the absorption of 3.10 × 102 kJ of heat. 3)the release of 4330 kJ of heat. 4)the absorption of 77.5 kJ of heat.

*asked on October 31, 2016* -
## math

The measures of the three angles of a triangle are given. Find the value of x and state whether the triangle is acute, obtuse, or right. x + 10, x − 20, x + 25 I got x is 55 and it is an acute angle. Is that correct?

*asked on October 11, 2016* -
## Pre-Calculus

A hemispherical bowl with a 30-centimeter radius contains some water, which is 12 centimeters deep. Find the volume of the water.

*asked on October 10, 2016* -
## Math

what is the largest 3 digit even number you can make with the digits 1,2, and 3?

*asked on September 28, 2016* -
## Maths (quadratic equation) need help

In an unknown fraction the denominator is one more than twice the numerator. When 2 1/10 is added to this fraction, the result is equal to the reciprocal of the unknown fraction. Find the unknown fraction. (Hint; the the numerator of the fraction to be the

*asked on May 31, 2016* -
## help science

3 simple steps for DNA duplication I have found so many answers but cant get a concise one. 1. separation - of 2 dna strands unzips ? 2. duplicates ? 3. zips back up ? and then a simple sentence about each

*asked on May 29, 2016* -
## 7th grade science final

review Question -- 3 simple steps for DNA duplication I have found so many answers but cant get a concise one. 1. separation - of 2 dna strands unzips 2. duplicates 3. zips back up and then a simple sentence about each

*asked on May 29, 2016* -
## Math Trigonometry

A plane flies in a direction of 85° from Chicago. It then turns and flies in the direction of 200° for 150 miles. It is then 195 miles from its starting point. How far did the plane fly in the direction of 85°? I am confused about aereal navigation. Can

*asked on May 20, 2016* -
## Math

The student mr. Davis class either walk or ride the bus to school the number of students ride the bus is a tenant in the number of students who walk is 12 is there a 450 students in the school how many students total can you expect to ride the bus

*asked on May 14, 2016* -
## scte

a 90 volt Hz source is connected to 0.1 Henry inductor.what is the current through the inductor?

*asked on April 26, 2016* -
## LO

a newspaper article to warn people against engaging with fraud

*asked on April 24, 2016* -
## A.P. Chem

Based on like dissolve like, determine if these compounds will be more soluble in water or an organic solvent. 1) Sodium Butyrate I think Water 2) Phenol I think organic 3) Aniline I think water 4) Sodium phenoxide I think water

*asked on April 12, 2016* -
## Math

Show using integration by parts that: e^3x sin(2x)dx = 4/26 e^3x (3/2 sin(2x) - cos(2x)) +c Bit stuck on this. Using rule f udv = uv - f vdu u = e^3x dv + sin(2x)dx f dv = v du/dx = 3e^3x v = -1/2 cos(2x) so uv - f vdu: = (e^3x)(-1/2 cos(2x)) - (-1/2

*asked on March 24, 2016* -
## Physics

A 5 kg block is being pulled on a frictionless surface by a string at an angle of 30o to the horizontal. The tension in the string is 30 N. What is the total work done on the block as it moves a distance of 10 m?

*asked on March 21, 2016* -
## calculus

the vector function r(t)=< 5 sin t, 3 sec t > , represents the position of a particle at time t. find the velocity v (t) and acceleration a (t). I don't know how to solve it without the t given. Please help

*asked on March 21, 2016* -
## Calculus

Rectangular sheet of metal 750mm by 300mm - find length of the sides of the squares to give max volume to the box, and find maximum volume of the box?

*asked on March 19, 2016* -
## Chemistry

If I am doing a fractional distillation, is the temperature of the first few drops of the distillation considered part of the boiling range? Or do you wait until later in the distillation?

*asked on March 16, 2016* -
## Chemistry

You start with a 20ml mixture of two compounds. After distillation you end up with 10ml of distillate 1 and 8.4ml of distillate 2. What is the relative volume percent of each compound in the pre-distilled mixture? (Do I just do: volume percent of

*asked on March 14, 2016* -
## Science

Is Gc (32.2 lbmft/lbfs^2) equal to gravity? I think it is, but I'm kinda confused about the whole concept. Could someone explain it to me? Thank you very much.

*asked on March 9, 2016* -
## Physics

Is Gc (32.2 lbmft/lbfs^2) equal to gravity? I think it is, but I'm kinda confused about the whole concept. Could someone explain it to me? Thank you very much.

*asked on March 9, 2016* -
## Chemistry

Why is methanol a good solvent to recrystallize biphenyl?

*asked on February 25, 2016* -
## MATHS

In a class of 30 learners,17 play football,15 play vollyball,12 play rugby.9 learners play vollyball only and 3 play rugby only.If all learners play at least one of the three sports.Use a venn diagram to find the number of learners who pray only vollyball

*asked on February 17, 2016* -
## Physics

A 6.80 x 10^4 kg space shuttle moving at 7.90 x 10^4 m/s reenters the earth's atmosphere 80.0 km above the earth's surface. What is the shuttle's total mechanical energy with respect to earth's surface? I know the answer is E= 2.173 x 10^12J But I don't

*asked on January 27, 2016* -
## Economics Macro

Suppose that real GDP per capita in the United States is $49,000. If the long-term growth rate of real GDP per capita is 1.6% per year, how many years will it take for real GDP per capita to reach $98,000?

*asked on January 25, 2016* -
## Statistics

On the third day of Statistics, my teacher gave to me….three French hens. Because she is in a hurry, she randomly selects three pets from the local pet store. Find the probability that she selected three French hens. Hens Chickens French 10 20 American

*asked on December 23, 2015* -
## mechanics

Short column of rectangular cross section 160mm by 60mm carrying point load of 40 KN at max eccentricity position along the longer axis so that no tensile stress is applied. I worked out max eccentricity as 26.66 mm from RH and LH, and compressive stress

*asked on November 26, 2015* -
## Mechanical engineering

An I section beam of 4m length with end supports is required to carry a point load of 50 KN at its mid pint. The maximum bending stress is limited to 85 MPa, and Modulus of Elasticity of the steel s 200 GPa. Evaluate maximum bending moment that will be

*asked on November 26, 2015* -
## Algebra 2

Solve system by substitution or elimination x+4y=13 2x+3y=6

*asked on November 13, 2015* -
## Algebra

If Angela runs up 5 steps of the escalator, then it takes her 40 seconds to reach the top of the escalator. If she runs up 14 steps of the escalator, then it takes her only 26 seconds to reach the top.

*asked on September 12, 2015* -
## Presbyterian Boys' Senior High

Q, P and R are three villages on a level ground. Q is 4km on a bearing of 040° from P, while R is 3km on a bearing of 130° from Q. Calculate the distance and bearing of P from R.

*asked on September 4, 2015* -
## math

Sarah Meeham blends coffee for Tasi-Delight. She needs to prepare 140 pounds for blended coffee beans selling for $5.07 per pound. She plans to do this by blending together a high-quality bean costing $6.50 per pound and a cheaper bean at $2.50 per pound.

*asked on July 14, 2015* -
## Maths

Have a question on complex numbers. Z1= 1+j2, Z2= 2+j5 Find total impedance in Cartesian and polar form of two impedances in parallel: 1/ZT = 1/Z1 + 1/Z2 I get to 39/58 + 83/58 j but then get a bit lost.

*asked on May 20, 2015* -
## chemistry

What mass of solute is contained in 250 mL of 0.895 M NH4Cl? I think that this is a molarity question. Molarity = mass of solute/volume of solution in L. 1 mL = 0.001 L so 250 mL * 0.001 L = 0.25 L 0.895 M = X (mass of solute)/ 0.25 but since the answer is

*asked on May 7, 2015* -
## Economics

can someone help me put (yuan depreciates against the dollar into one stanza of a song.

*asked on May 5, 2015* -
## physics

A fixed mass of gas has a pressure of 8700 Pa, a volume of 10.5 m3 and temperature of 68 °C. The pressure and volume of the gas are changed to 9 243 Pa and 14.4 m3. The new temperature of the gas is

*asked on May 4, 2015* -
## chemistry

An atom whose nucleus contains 7 neutrons and which has a mass number of 12 is an isotope of what element?

*asked on April 28, 2015* -
## chemistry

What is the approximate effective nuclear charge for arsenic ?

*asked on April 28, 2015* -
## chemistry

q4 What element has the greatest first ionization energy? Li Na K Rb Cs

*asked on April 28, 2015* -
## chemistry

Consider an electrochemical cell based on the reaction: 2H+(aq) + Sn(s) = Sn2+(aq) + H2(g). Which of the following actions would NOT change the measured cell potential? lowering the pH in the cathode compartment addition of more tin metal to the anode

*asked on April 20, 2015* -
## chemistry

What is the oxidation state of the vanadium atom in VO4−

*asked on April 16, 2015* -
## chemistry

Consider an electrochemical cell based on the reaction: 2H+(aq) + Sn(s) = Sn2+(aq) + H2(g). Which of the following actions would NOT change the measured cell potential? lowering the pH in the cathode compartment addition of more tin metal to the anode

*asked on April 16, 2015* -
## chemistry

Which element is reduced in the unbalanced reaction below? I− + MnO4− + H+ = I2 + MnO2 + H2O I no reduction occurred in this reaction O H Mn

*asked on April 16, 2015* -
## chemistry

How many electrons does the Au+ ion have ? Enter an integer below without any letters or symbols.

*asked on April 15, 2015* -
## Physics

I have a question on fluids. Water in a section 1.2m wide, 2m high. retained by sluice gate that can pivot about its base. There is a retaining cable at the top of the gate. Determine tension in the retaining cable at the top of the gate when the depth of

*asked on April 13, 2015* -
## Mechanical Principles

I have a question on fluids. Water in a section 1.2m wide, 2m high. retained by sluice gate that can pivot about its base. There is a retaining cable at the top of the gate. Determine tension in the retaining cable at the top of the gate when the depth of

*asked on April 13, 2015* -
## Physics

Is this correct?? Metal block weighs 500g in air and 446g completely submerged in water. Calculate density and relative density. Density of water = 1000kg/m3 BF (Buoyant force) will be 500g-446g = 0.54 g (or 0.054 kg). For volume: If BF =

*asked on April 10, 2015* -
## Chemistry

Laughing gas (nitrous oxide, N2O) is sometimes used as an anesthetic in dentistry. It is produced when ammonium nitrate is decomposed according to the reaction NH4NO3(s) −! N2O(g) + 2H2O(§¤) . How much NH4NO3 is required to produce 54.5 g of N2O?

*asked on April 9, 2015* -
## Chemistry

027 (part 1 of 3) 10.0 points Copper reacts with silver nitrate through single replacement. If 3.03 g of silver are produced from the reaction, how much copper(II) nitrate is also produced? Answer in units of mol. 028 (part 2 of 3) 10.0 points How much Cu

*asked on April 9, 2015* -
## Chemistry

Calculate the mass of water formed by the complete reaction of 572 g of propane (C3H8) with excess oxygen. (Write a balanced equation.) Answer in units of g.

*asked on April 9, 2015* -
## Mechnical principles

Mtal block weighs 500g in air and 446g completely submerged in water. Calculate density and relative density. I know relative density is density of material/density of water (1000kg/m-3)

*asked on April 9, 2015* -
## chemistry

At a certain elevation, the boiling point of water is 98.5°C. How much energy is needed to heat 35.0 mL of water to the boiling point at this elevation if the water initially was at 23.4°C? (Cp=75.38J/(mol*C), d= 1.00g/mL)

*asked on April 1, 2015* -
## Calculus 1

How do you find the derivative of 1/3(x^2+2)^3/2 ? Please help

*asked on March 31, 2015* -
## physics

A 5.0 Ω resistor, a 9.0 Ω resistor, and a 12.0 Ω resistor are connected in parallel across a 24.0 V battery. a) What is the equivalent resistance of the circuit? Answer in units of Ω b) What is the current in the 5.0 Ω resistor? Answer in units

*asked on March 24, 2015* -
## chemistry

The average swimming pool has a volume of about 28,000 gallons. Suppose a swimming pool was filled with pH 7.00 water. However, you need to adjust the pH to 4.75. How much acid pool acid (which is 1.00 M HCl) do you need to add to the pool? The units are

*asked on March 22, 2015* -
## chemistry

You need to determine the pKa of a weak, monoprotic acid. You add 0.500 moles of the acid to 1.00 L of water. The resulting pH was 1.87. What is the pKa of this weak acid? You may ignore the autoionization of water. 2.74 3.43 5.38 2.01 1.87

*asked on March 22, 2015* -
## chemistry

All of the following acid-base pairs are examples of buffers EXCEPT: (Question from "Cracking the MCAT, 2010-2011 edition" by The Princeton Review) HCl/NaCl CH3CO2H/NaCH3CO2 HF/NaF H2CO3/NaHCO3 I chose ch3co2h/nach3co2

*asked on March 22, 2015* -
## chemistry

What is the pH of 500 mL of water that had 0.00150 grams of NaOH added to it? The units are pH units with an error interval of 0.1 units. 0.00150 divided by 40NaOH 3.75e-5 divided that by 500= 7.5e-8 -log7.5e-8 =7.12 im lost on the last step

*asked on March 22, 2015* -
## chemistry

The Ka of hypochlorous acid (HClO) is 3.00×10-8 at 25.0°C. Calculate the pH of a 0.0385 M hypochlorous acid solution. a.1.41 b.7.52 c.-1.41 D.4.47 E. 8.94 I got B 7.52 but i feel like im wrong

*asked on March 22, 2015* -
## chemistry

A 300 mL solution of 0.0500 M HCl is titrated with 1.00 M KOH. How many mL of the KOH solution will be needed to reach the equivalence point of this titration? A.5 mL B.10 mL C.50 mL D20 mL E15 mL The answer i got was E. 15ml

*asked on March 22, 2015* -
## chemistry

Which of the following acids is expected to be the strongest acid? CH2F-COOH CF3-COOH CH3-COOH CCl3-COOH CBr3-COOH i chose ccl3-cooh

*asked on March 22, 2015* -
## chemistry

Which of the following chemicals are bases or can behave like bases? You may select more than one compound. KOH PO43- NH3 F-

*asked on March 21, 2015* -
## chemistry

Which of the following chemicals are bases or can behave like bases? You may select more than one compound. Cu2+ RbOH CH3COO- Br-

*asked on March 21, 2015* -
## chemistry

Which of the following chemicals are strong bases? You may select more than one compound. CH2=CH2 Ca(OH)2 NH3 RbOH

*asked on March 21, 2015* -
## chemistry

The Ka of hypochlorous acid (HClO) is 3.00×10-8 at 25.0°C. Calculate the pH of a 0.0385 M hypochlorous acid solution. A.1.41 B.7.52 C.-1.41 D.4.47 E.8.94 I chose B

*asked on March 21, 2015* -
## physics

How many kilometers would you have to go above the surface of the earth for your weight to decrease to 39{\rm \\%} of what it was at the surface? Express your answer using two significant figures.

*asked on March 9, 2015* -
## physics

A highway curve with radius 1000ft is to be banked so that a car traveling 56.0mph will not skid sideways even in the absence of friction At what angle should the curve be banked?

*asked on March 9, 2015* -
## Physics

A baseball player with a mass of 79 kg slides into homeplate. The coefficient of kinetic friction between the player and the ground is μk = 0.632. If the player comes to rest after 1.04 s, what is his initial speed?

*asked on March 4, 2015* -
## Calculus Physics

Imagine a spaceship on its way to the moon from the earth. Find the point, as measured from the center of the earth, where the force of gravity due to the earth is balanced exactly by the gravity of the moon. This point lies on a line between the centers

*asked on March 3, 2015* -
## Calculus Physics

A glass of orange juice is on the floor of a subway car traveling along a straight path at constant velocity. Everything's fine. The coefficient of static friction between the glass and the floor is 0.32. The subway suddenly accelerates forward. What is

*asked on March 3, 2015* -
## chemistry

One of the ways to produce iron is to take iron(II) oxide and react it with carbon monoxide to get pure iron and carbon dioxide. The reaction is FeO(s) + CO(g) = Fe(s) + CO2(g). What is the partial pressure of CO2(g) if 2.00 atm of CO and excess iron(II)

*asked on March 1, 2015* -
## chemistry

Lead iodide is a relatively insoluble compound. It can dissolve from the solid phase into the aqueous phase with a Keq of 0.00027. If the concentration of lead iodide in the aqueous phase 0.125 M, then: a. we need more information to determine the progress

*asked on February 28, 2015* -
## chemistry

Equilibrium is: a dynamic condition in which the concentration of the reactants is equal to the concentration of the products. a static condition in which the concentration of the reactants is equal to the concentration of the products. a static condition

*asked on February 28, 2015* -
## Science check

Water in the upper zones of the ocean will have more oxygen than water in deeper zones. true or false i think true.

*asked on February 27, 2015* -
## physics

PART ONE: A charge of 4.70μC is at the origin and a second charge of −2.85μC is on the positive x-axis 1.08 m from the origin. Find the magnitude of the electric field at a point P on the y-axis 0.640 m from the origin. The value of the Coulomb

*asked on February 27, 2015* -
## chemistry

The following equilibrium exists in a closed container: N2(g) + O2(g) = 2NO(g), ΔH = +181 kJ/mol. Which of the following perturbations would favor the formation of NO(g)? (practice MCAT question from The Princeton Review MCAT Science Workbook, 2009

*asked on February 26, 2015* -
## chemistry

Suppose you have the following reaction at equilibrium: N2(g) + 3H2(g) = 2NH3(g), ΔH = −22 kcal/mol What changes are expected to occur if the temperature of the system was decreased. You may select multiple answers. The concentration of NH3(g) would

*asked on February 25, 2015* -
## chemistry

1) C2H2O4(aq) = H+ (aq) + C2HO4- (aq); Keq = 6.5E-2 2) C2O42- (aq) + H+ (aq) = C2HO4- (aq); Keq = 1.64E+4 then what is the equilibrium constant for the following reaction: C2H2O4(aq) = 2H+ (aq) + C2O42- (aq)? Keq = 1070 Keq = 227 Keq = 2.21E-4 Keq =

*asked on February 25, 2015* -
## chemistry

The pollutant NO is formed in diesel engines. The reaction fixes atmospheric nitrogen with oxygen to form NO. The reaction is: N2(g) + O2(g) = 2NO(g). If the equilibrium constant for this reaction at elevated temperatures is 5.60E-11, then what is the

*asked on February 25, 2015* -
## chemistry

How is the reaction quotient used to determine whether a system is at equilibrium? The reaction is at equilibrium when Q > Keq. At equilibrium, the reaction quotient is undefined. The reaction quotient must be satisfied for equilibrium to be achieved. The

*asked on February 25, 2015* -
## chemistry

Which of the following statements is not true? 1.Chemical equilibria are examples of reversible processes. 2.When multiple reaction steps are in equilibrium, then the equilibrium constant for the net reaction is the product of the individual reactions.

*asked on February 25, 2015* -
## Calculus Physics

A 1559-kg car moves at 15.0 m/s. What is the magnitude of the horizontal net force needed to bring the car to a halt in a distance of 50.0 m?

*asked on February 20, 2015* -
## Calculus Physics

A particle is subject to a time-dependent force: F(t)=5t√. If the particle's mass is 7 kg, what will its velocity be at t=6.7 seconds, assuming its initial velocity at t=0 is equal to 0.

*asked on February 19, 2015* -
## Calculus Physics

A particles with mass 3.7 kg moves in the x direction according to the following function: x(t)=−7+4t+3t2−4t3. (the units of each coefficient are meters, and time is measured in seconds). At time t=7.8, what is the net force acting on the particle?

*asked on February 18, 2015*