# Posts by james

Total # Posts: 2,462

**Statistics**

A researcher conducts a test on the effectiveness of a cholesterol treatment on 114 total subjects. Assuming the tails of distributions are normal distribution, is there evidence that the treatment is effective? What is the Null and alternative hypothesis.

**geometry**

it is d

**Physics**

A box slides along a rough floor with initial kinetic energy of 7 J. A person pushes on the box, in the same direction as its velocity doing 25 J of work. The velocity of the box is doubled. Find the magnitude of the work done by friction.

**Finance**

That answer is way off, grow up!

**Math**

Convert the polar equation to rectangular form: r = -2cosø - 2sinø

**Economic**

What are welfare payments and we're South African government providing and to whom

**Maths**

A collection of coins consisting of 10-cent, 20-cent and 50-cent pieces has a value of $4.50. The number of 20-cent pieces is twice the number of 10-cent pieces and the number of 50-cent pieces is 3 less than twice the number of 10-cent pieces. How many 10-cent, 20-cent and 50...

**math**

Brittany made 75 at the first (100*3/4) After Ava gave her, Brittany had 120 (75+(9/20*100)) After Brittany gave Ava, Ava had 85 (55+(25%*120)) At the end Brittany had 90 and Ava had 85, so she 5 more

**Maths**

Luisa travels 25 km in 3hours 45 mins. She walks part of the way at 4 km/h and cycles the rest at 12 km/h. How far did she walk?

**Maths**

I got 37.0313 using your equation But in the text book the answer is 10km How to work it out using linear equations

**Maths**

Luisa travels 25 km in 3 3 4 hours. She walks part of the way at 4 km/h and cycles the rest at 12 km/h. How far did she walk?

**Math**

a rectangular tank with a square base of side 60 centimeters and a height of 45 centimeters is one third filled with water. water from a tap flows into the tank at 6 liters per minute. how long will it take to fill the tank completely? (1 liter=1,000 cm3

**math**

Water is taken from a well 11m deep in a bucket,the rope winding up to a drum 35cm in diameter. A)Through what angle does the handle turn in winding up 1m of rope? B)How many revolutions of the handle does it take to bring the bucket up from the bottom? C)If the arm of the ...

**Maths**

Three consecutive terms of a Geometric Progression are ? 6, p and ? 32 . find the value of p.

**Physics**

Mass m2 rests on an incline and attaches to a string that goes over a pulley, where mass m1 hangs on the other side of the incline. Assume that there is no friction between m2 and the incline, that m2 = 5.1 kg, m1 = 0.9 kg, the radius of the pulley is 0.10 m, the moment of ...

**math**

6cm diameter discs are cut from a sheet 130cm long and 70cm wide.(a)How many discs can be cut in this way (b) what area of the sheet is wasted? (My working so far). Area of rectangle=L*B 130*70=9100cm^2 area of circle=22/7 *(6/2)^2=28.286cm^2 (a)no of discs cut=9100/28.286=321...

**maths**

Three consecutive terms of a Geometric Progression are − 6, p and − 32 . find the value of p.

**Physics**

Can someone help me solve this? I've tried it a few times, but I keep getting answers that seem off. Like, for example, I'm getting 2.339 for part A, and it just seems completely off. So if you know the right formulas and can walk me through this, I'd appreciate it...

**Science**

Assuming all volume measurements are made at the same temperature and pressure, what volume of hydrogen gas is needed to react completely with 3.75 L of oxygen gas to produce water vapor?

**Chemistry**

Calculate the number of grams of nitrogen gas, N2, in a container that has a volume of 7.50 L at a pressure of 1200 mm Hg and a temperature of 38.2 degrees Celsius. (R=0.0821 L*atm/mole*K)

**algebra**

Given: 3(x-2y)+3x=y-2(x+4y), find the ratio of y to x

**Algebra**

6. One angle measures 54 more than 3 times another angle. The angles are supplementary. What are their measures? 11. A piece of string is 112 inches long. Isabel wants to cut it into 2 pieces so that one piece is three times as along as the other. How long is each piece?

**Physics**

I'm not getting the right answer for part b. Could someone help me understand this part better?

**Physics**

Could someone show me how to work this? It's for a study guide I'm practicing, and I just can't seem to get the correct answer. The position of a 0.63 kg object attached to a spring is described by [x = (1.09 m) cos(3.11πt)] a) Find the object’s position ...

**math**

rude.

**math**

3 cm which its area increasing when its edge is 12 cm long

**science**

The alleles for brown eyes (B) are dominant, while those for blue eyes (b) are recessive. If Lesley’s mother has the genotype BB and her father has the genotype bb, what is Lesley’s genotype? What is her phenotype?

**Medical physics**

1.A hypodermic needle of lenght 0.020m and inner radius 3.0 x10^-4 is used to force water at 20 degree celcious into the air at a flow rate of 1.0 x10^-7m^2 s-1 (a) what is the average velocity in the needle?(assume laminar flow), (b) what is the pressure drop necessary to ...

**Medical physics**

1.A hypodermic needle of lenght 0.020m and inner radius 3.0 x10^-4 is used to force water at 20 degree celcious into the air at a flow rate of 1.0 x10^-7m^2 s-1 (a) what is the average velocity in the needle?(assume laminar flow), (b) what is the pressure drop necessary to ...

**Chemistry**

A woman expends 96 kJ of energy in walking a kilometer. The energy is supplied by the metabolic breakdown of food intake and has a 35 % efficiency. If the woman drives a car over the same distance, how much energy is used if the car gets 8.7 km per liter of gasoline? The ...

**math**

The coordinates of (triangle) ABC are A(-3,-1 ) , B( 5,1 ) and C (2,4) (i) Calculate the length of AB , BC and AC (ii) Hence, show that (triangle) is a right- angled triangle

**chemistry**

50.0 mL of an unknown HCl solution was titrated with 0.449 M NaOH. To reach the equivalence point, 38.4 mL of the NaOH was used. What was the concentration of the HCl?

**Chem**

0 = [4440g*0.803*(Tf-98.8)] + [2.00*4.186*(Tf-24.8)] Tf = 98.6C

**Chem**

A 4.44 kg piece of granite with a specific heat of 0.803 J g-1 °C-1 and a temperature of 98.8°C is placed into 2.00 L of water at 24.8°C. When the granite and water come to the same temperature, what will the temperature be?

**Physics**

lol yoooo you in brahmia's physics class bruh pay attention in class yo

**Physics**

Can someone walk me through how to solve this? Any help is much appreciated! Two masses moving along a straight line undergo a front-to-back collision. The masses are m1= 60.0 kg, with initial velocity v1 = 17.0 m/s, and m2 = 26.0 kg, with initial velocity v2 = 7.0 m/s. After ...

**Medical physics**

A silver cube (density of silver is 10 g/cm3) with side length of 3 cm weighs more than an aluminium cube (density of aluminium is 2.96 g/cm3) with side length of 4 cm. The cubes are each suspended by a string and allowed to be completely immersed in two identical jars ...

**Physics**

It's 0%, I've done the exact same question, I think there's a typo.

**Algebra**

ITS C KELSEY, You made me get my question wrong, f you

**Physics**

A block of mass 13.9 kg slides from rest down a frictionless 40.0° incline and is stopped by a strong spring with a spring constant 32.3 kN/m (note the unit). The block slides 7.80 m from the point of release to the point where it comes to rest against the spring. When the...

**Physics**

A M2= 6.40 kg mass is released from rest at height h = 6.60 m . Using the law of conservation of energy, determine the speed of the M1= 2.70 kg mass just as the M2= 6.40 kg mass hits the ground.

**college algebra**

How much should be deposited in an account paying 3.5% interest, compounded quarterly, in order to have a balance of $ 6,000after 17years and 3months?

**math**

A cube with length 4cm is divided into 8 identical cubes.How much greater is the combined surface area of the 8 smaller cubes than the surface area of the original cube?

**L.A**

you would you think someone would do your work? you did not even put any effort into this question. You barely even put effort into typing the question! Stop being lazy!

**math**

A rectangle measuring 7cm by 4cm is enlarged by a ratio of 2:1.what is the area of the enlarged rectangle.

**Physics**

Can someone help me solve this one? I've tried it a few times, but I don't think I'm getting it right. A block of mass M = 2.2 kg starts from rest at a height of 3.6 m on a fixed inclined plane. The coefficient of kinetic friction between the block and the incline ...

**Physics**

Can someone walk me through how to work this? It's worded weirdly and I'm not sure how to solve it. Mass M1= 2.2 kg lies on a frictionless table, pulled by another mass M2= 4.1 kg under the in of Earth's gravity. a) What is in N the net force acting on the system ...

**Physics**

Can someone walk me through how to work this? A block is being pushed up a frictionless incline by an applied horizontal force, F=12.7N. (The angle is θ = 23.80° and the mass is 1.70kg. a) How many forces are acting on the block? b) How many of those forces are along ...

**Physics**

Can someone help me with this problem? It requires a lot of visualizing and I've never been great at problems like that. A pair of blocks of mass m1 =29.0 kg, and m2 =58.0 kg, are being pushed on a horizontal surface by a constant forces of magnitude F=87.0 N. The angle &#...

**Physics**

I think I've found everything but e. Here is my work a) acceleration = v-u/t a = 1.95/1.22 a = 1.6 b) 2, gravity and the normal force c) F = m(g – a) F= 42(10-1.6) F = 352.8 d) acceleration = v-u/t a= 1.95/7.8 a= .25 F= m(g-a) F= 42(10-.25) F= 409.5 Does anyone else ...

**Physics**

A 42 kg man stands on a bathroom scale in an elevator. Starting from rest at the bottom floor, the elevator ascends, attaining its maximum speed of 1.95 m/s in 1.22 s. It travels with this constant speed for the next 7.80 s. The elevator then slows down for 2.20 s and comes ...

**Physics**

Hey, I'm studying for my physics class, and I'm not sure how to solve this problem. Can someone walk me through it please? I'd really appreciate any help! John throws a baseball from the edge of a cliff with an initial velocity of 17.0 m/s at an angle 27.0° ...

**math**

If Owen gives $40 to Charley, the will have an equal amount of money. If Charley gives $80 to Owen, the ratio of Owen's money to Charley's money will be 4-1.How much money does Owen have in the beginning? Work: I don't have much but X=Owen C=charley X=C-40 4C=O+80

**Chemistry**

An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% Carbon and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of -5.20 ...

**Math**

What is the domain of x/(x-1)? Is it all x <> 1?

**Physics**

This one has been confusing me, can someone walk me through it? I'd like to know which formulas I need to use and everything. A 121.0 -kg crate is sitting at rest on a ramp leading to the back of a truck. a) How many forces are acting on the crate while it is at rest? b) ...

**Physics**

Hey! I've tried using equations such as weight=m*g for this problem, but I don't think I'm doing it right. Can someone help? A helicopter was seen carrying a heavy bag of sand (1210.0 kg). A student figured that the acceleration of the sand bag then was 1.4 m/s2 in...

**math**

25

**Biology**

explain the consequence of x chromosome inactivation in terms of the proteins encoded by the x chromosome genes?

**Algebra 2**

Describe an infinite geometric series with a beginning value of 2 that converges to 10. What are the first 4 terms of the series?

**Science**

Wow, you dumb people. You're all wrong. The answers are... 1. A 2. C 3. B 4. False I followed Aaron and got a 0%. Aaron, you're a dick.

**Dynamics**

The 25-lbf block has an initial speed for v0 = 10 ft/s when it is midway between springs A and B. The coefficient of static and kinetic friction between the plane and the block are μs = 0.45 and μk = 0.4, respectively. After striking spring B, the block rebounds and ...

**Microcomputer applications**

thank you

**Microcomputer applications**

Do you know if there is an online tutorial for the book Office 2013 Marquee by Rutosky, Sequin, Roggenkamp, Rutosky

**English(ASAP)**

The answer is b I just did it

**chem**

nevermind i got it, accidentally put in 5.86 instead of 5.96 :)

**chem**

Calculate the energy of a photon of green light with a frequency of 5.96 ✕ 10^14 s−1 I keep getting 3.88e-21, but the quiz keeps saying I'm wrong...

**accounts**

On January 1, 2012, the organizers of the Parsons Corporation obtained their charter and issued 10,000 shares of $1 par common stock for $4 per share. During 2012, the corporation earned $30,000 in cash revenue and paid $20,000 in cash expenses, not including income tax. The ...

**Probability**

Alfred and Bob toss a coin alternatively, and whoever gets a head first will win. They play many times and whoever loses in the previous play will toss first at the next play. If Eric tosses first at the first play, then what is the probability that Eric will win at the 6th play?

**investing**

How many years, correct to 1 decimal place, will it take for K54,321 invested at a compound interest of 13% per annum, to amount to K98,765

**Science**

4

**physics**

A jet plane lands in an airport with a speed of 125 m/s and can accelerate uniformly at a maximum rate of -9.8 m/s2 as it comes to rest. What should be the minimum length of the runway so that the jet plane can land in the airport safely?

**Science**

I HAVE SAME QUESTION

**Science**

ITS EATHER coarse grains OR fine grains

**Science**

WELL WE KNOW IT COOLED SLOWLY AND...

**Physics**

A 7.1 kg watermelon is placed at one end of a 5.9 m, 244 N scaﬀolding supported by two cables. One supporting cable is at the opposite end of the scaﬀolding, and the other is 0.54 m from the watermelon. How much tension is in the cable at the end of the sca&#...

**chem**

1. A 4.61 g sample of one of the substances listed in the table below was heated from 21.3°C to 315.7°C, requiring 190 J to do so. What substance was heated? I got mercury(l) 2. Calculate the energy required in joules and calories to heat 33.9 g of aluminum from 30.7&...

**Math**

40

**Maths and Physics**

Your clue is impossible, water release at a velocity of 20m/s cannot lift a 10 kg garbage can under earth's gravity. F=lambda 2v^2 (assuming elastic collision) = 2mv^2/d = 2(dm/dt)(v^2)/u = 20N which can lift a can of 20/9.81 kg so your water can only lift a max of 2.04 kg...

**Chemistry re-post**

Consider the titrtation of 25.0mL of 0.0100M Sn2+ by 0.0500M TI3+ in 1 M HCL, using Pt and Saturated Calomel Electrodes to find the endpoint. F=96486.7 Cmol E0 Sn4+/Sn2+ =0.15V E0 TI3+/TI+ = 1.28 Esce = 0.241V R=8.3141 J K Mol (a) Write the balanced reaction. Sn4+ + 2e- <...

**Chemistry (Electrochemistry)**

Consider the titrtation of 25.0mL of 0.0100M Sn2+ by 0.0500M Ti3+ in 1 M HCL, using Pt and Saturated Calomel Electrodes to find the endpoint. F=96486.7 Cmol E0 Sn4+/Sn2+ =0.15V E0 TI3+/TI+ = 1.28 Esce = 0.241V R=8.3141 J K Mol (a) Write the balanced reaction. Sn4+ + 2e- <...

**Chemistry**

Consider the titrtation of 25.0mL of 0.0100M Sn2+ by 0.0500M Ti3+ in 1 M HCL, using Pt and Saturated Calomel Electrodes to find the endpoint. F=96486.7 Cmol E0 Sn4+/Sn2+ =0.15V E0 TI3+/TI+ = 1.28 Esce = 0.241V R=8.3141 J K Mol (a) Write the balanced reaction. Sn4+ + 2e- <...

**Chemistry (Re-post)**

The distribution co-efficient of butanoic acid (pKa = 4.8) between water and two organic solvents are given below; Benzene D= 3.0 Octanol D= 6.2 a) which organic solvent is expected to extract the acid most efficiently from the water? explain your answer. So you expect that ...

**Chemistry**

The distribution co-efficient of butanoic acid (pKa = 4.8) between water and two organic solvents are given below; Benzene D= 3.0 Octanol D= 6.2 a) which organic solvent is expected to extract the acid most efficiently from the water? explain your answer. I understand that D ...

**Chemistry**

Imagine that you have a 7.00L gas tank and a 4.00L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 145atm , to what pressure should you fill the...

**Chemistry (Electrochemistry)**

The thickness of a pure Ag plate on a base metal is to be determined by controlled potential coulometry. The metal sheet is masked except for a circular area, 0.5cm in diameter. Electrical connection is made to the metal and the sheet is clamped in a cell so that the unmasked ...

**geometry**

From an apartment window 24 m above the ground, the angle of depression of the base of a nearby building is 38 degrees and the angle of elevation is of the top is 63 degrees. How tall is the nearby building?

**Math**

6 9/8-25/6=

**AP Calc**

For the curve f(x)=x ln x+(1-x)ln(1-x), find the value of x in the interval 0<x<1 where f(x) has a minimum.

**algebra**

Traveling downstream a certain boat went 21 mph. Traveling upstream it went only 5 mph. Find the speed of the boat in still water and the speed of the current.

**Chemistry**

If 25.00 ml of H2SO4 solution is titrated to an end point with 32.16 ml of 0.1986 M NaOH, what is the molarity(M) of the H2SO4 acid?

**Chemistry**

Which of the following factors affect the solubitity? a)temperature of the solutions b)polarity of the solvent vs solute molecules c)partial pressure of the gas above the solution d) all of the above

**Math**

A boy is dividing M&Ms between himself and his sister. He gives 2 to his sister and takes 2 for himself. He gives 2 to his sister and takes 4 for himself. He gives 2 to his sister and takes 6 for himself, and so on. (b) After n rounds, how many M&Ms does his sister have and ...

**Biology**

The Deflex binds with the receptors in the synapses which means the transmitter can no longer bind to the receptors, this means that the nerve impulse cannot be sent along the relay neurone. Deflex also binds to the neurotransmitter once released and breaks it down.

**Physics**

A ball of mass m is attached to a spring with a spring constant k. The system is attached to a thin vertical axis as shown in Figure 4. In its equilibrium vertical position the spring length is L. The axis starts to rotate with a constant angular frequency ω. Find the ...

**AMA**

A force of 1.24 N pushes against an object with a mass of 0.16 kg for 3.00 min. The object does not move. What is the work done on the object by the force?

**Math**

Limit(7x+6x^2) / (7x^2+6x) x->inf

**Sociology**

Alright. Thanks Writeacher.

**Sociology**

Are Ethnic Groups the same as Societies?