Posts by Danny
Total # Posts: 890

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. Explain, in complete ... 
Trig
Thank you Reiny 
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. 
maths
Maria is playing chess in mobile 
Trig
Yes 
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 
music
Thank you so much "Sans the Skeleton" I got a 100% :) 
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 
6th grade math
a) 10 nickels; 20 dimes b) $4.50 (10 nickels; 40 dimes) c) $2.50 
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. Because their genomes have... 
physics
I am not getting the questation plzzzzzz give the formula plzzzz 
History
??? 
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 
English Grammar 5th grade
Positive Comparative Superlative of the words I first wrote on my comment, Thanks! 
English Grammar 5th grade
making comparisons like big, bigger, biggest. Sorry by not explaining good. 
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! 
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? 
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 coastline harbor notify ... 
English
Since you are not willing to share the entire task, we cannot assist you at all. Well, you may also turn to the paid services. As far as I know Prime Writings is really popular among the students. 
Biology
1. How do mutations play into the fitness of an organism? 2. Describe how variation, selection and time fuel the process of evolution. 
Biology
1. How do mutations play into the fitness of an organism? 2. Describe how variation, selection and time fuel the process of evolution. 
Social Studies Help!!
Detroit what are you talking about? You're on here preaching about cheating and whatnot when you can barely spell and you're on here cheating also. 
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 
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? 
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? 
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 package that is 40in ... 
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 package that is 40in ... 
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. 5)the release of ... 
Math
I never ask for help like this but i really need it im so lost and have more to do than i can handle 
Math
Lesson 8: Solving Inequalities Unit Test CE 2015 Algebra 1 Unit 4: Solving Inequalities i need answers im 9 lessons behind in math and my mom just had surgery and the house is a mess if anyone understands please help!!!! ): i just dont have time 
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? 
PreCalculus
A hemispherical bowl with a 30centimeter radius contains some water, which is 12 centimeters deep. Find the volume of the water. 
Math
what is the largest 3 digit even number you can make with the digits 1,2, and 3? 
vocab help
Ice floats in water just like wood floats on : A. Water B. Ice C. Wood D. On the bottom My Answer is A 
Maths
n 
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 x) 
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 
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 
Math Trigonometry
Thank you a lot you saved my life. 
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 someone ... 
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 
MATH HELP ASAP
Btw or lesson 4 unit 3: Understanding slope A: 2 C:1 A:2/3 B:1 D:3 trust me I just took the quick check right now and these are the answers. Hope ya'll pass the 8th grade! 
scte
a 90 volt Hz source is connected to 0.1 Henry inductor.what is the current through the inductor? 
LO
a newspaper article to warn people against engaging with fraud 
L.A
anonymous is correct thx 
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 
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 cos(2x))(3e^3x) Don't ... 
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? 
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 
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? 
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? 
Chemistry
Okay, so then the volume percent is 10/20 and 8.4/20? 
Chemistry
What do you mean? It doesn't have any information about the water added? So is the percent volume 10/20 and 8.4/20, or do I need water for that too? I'm sorry but you've confused me more than I already am. 
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 predistilled mixture? (Do I just do: volume percent of mixture1=10/20 and volume ... 
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. 
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. 
Math
I'm not really sure what you're trying to solve for but heres what I think. 12 (.5%)•(.5/.75) =(0.06)•(0.67) = 0.0402 and maybe multiply by 100 to get = 4.02 
science
22.98977 amu 
Chemistry
Why is methanol a good solvent to recrystallize biphenyl? 
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 and rugby 
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 ... 
Economics Macro
Suppose that real GDP per capita in the United States is $49,000. If the longterm 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 $98,000? 
MATH
105 calories 
Statistics
I found the chisquare table, what would I put for the number of cells ? Im a little lost thanks :) 
Statistics
On the third day of Statistics, my teacher gave to me….three French hens. Because she is in a hurry, she randomly selects three pets from the local pet store. Find the probability that she selected three French hens. Hens Chickens French 10 20 American 30 40 In order to ... 
Science
Thanks nun yah! 100% 
mechanics
Short column of rectangular cross section 160mm by 60mm carrying point load of 40 KN at max eccentricity position along the longer axis so that no tensile stress is applied. I worked out max eccentricity as 26.66 mm from RH and LH, and compressive stress as 4.167 MPa. The ... 
Mechanical engineering
An I section beam of 4m length with end supports is required to carry a point load of 50 KN at its mid pint. The maximum bending stress is limited to 85 MPa, and Modulus of Elasticity of the steel s 200 GPa. Evaluate maximum bending moment that will be applied, and state its ... 
Algebra 2
Solve system by substitution or elimination x+4y=13 2x+3y=6 
history
How did 18th and 19thCentury European imperialism help to cause nationalism in Asian and African countries? A) It promoted free trade among the imperial colonies. B) It established Christianity as the common religion. C) It caused intense patriotic feelings toward the ... 
Physical Science
fuuck you !@#$%^&h 
Algebra
If Angela runs up 5 steps of an escalator, 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. How many seconds would it take Angela to reach the top if she did not run up any ... 
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. 
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. 
math
Sarah Meeham blends coffee for TasiDelight. 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 highquality bean costing $6.50 per pound and a cheaper bean at $2.50 per pound. To the nearest pound... 
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. 
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 to be in grams, I ... 
Economics
can someone help me put (yuan depreciates against the dollar into one stanza of a song. 
Science
Yes, the answers to this entire quick check were 1.A 2.D 3.C 4.B 
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 
chemistry
An atom whose nucleus contains 7 neutrons and which has a mass number of 12 is an isotope of what element? 
chemistry
What is the approximate effective nuclear charge for arsenic ? 
chemistry
q4 What element has the greatest first ionization energy? Li Na K Rb Cs 
Science
The answers to the severe weather quiz are the following. I just took this quiz and I got a 100% A. Trust me guys. 1.C 2.C 3.B 4.B 5.A 6.B 7.B 8.D 9.C These answers will give you a 100. 
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 compartment any of the ... 
chemistry
What is the oxidation state of the vanadium atom in VO4− 
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 compartment any of the ... 
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 
chemistry
How many electrons does the Au+ ion have ? Enter an integer below without any letters or symbols. 
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 water is 1.8m. ... 
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 water is 1.8m. ... 
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 500g446g = 0.54 g (or 0.054 kg). For volume: If BF = Density(water)*V*g then V = BF/density... 
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? Answer in ... 
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 is required in this ... 
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. 
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/m3) 
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) 
Calculus 1
How do you find the derivative of 1/3(x^2+2)^3/2 ? Please help 
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 of A 
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 liters. convert ...