# Posts by JC

Total # Posts: 148

**physics**

A cyclist in an Olympic race is moving in a circular track of radius 80 m with speed 72 km/h. He has to lean from the vertical approximately through an angle of... ANS: tan-1(1/2) How is tan-1(1/2) derived in this answer?

**Physics**

Thanks, Scott!!

**Physics**

An ideal string passes over a fixed pulley and carries masses M1 = 12kg and M2 = 8kg tied at its end. Calculate the acceleration of masses and tension in the string when released (g=10m/s2) I know the answers are a = 2 m/s^2 T = 96 N But I don't know how to get there

**Chemistry**

Determine how many mL of 0.102 mol NaOH solution is needed to neutralize 35.0 mL of 0.125 mol H2SO4 solution.

**Chemistry**

48.0 mL of Ca(OH)2 solution was titrated with 19.2 mL of 0.385 mL mol HNO3. Determine the molarity of the Ca(OH)2 solution.

**Physics**

9.58 sec.

**Physics**

9.58

**Math**

It's 4x+4

**chemistry**

how much oxygen gas wil be produce from the decomosition of 50 grams of pottasium chlorate

**Physics ( Thickness of a Spherical Shell)**

Aluminum floater: A spherical shell with an outer radius R=2 cm is made of aluminum (mass density of Al is 2.7 g/cm3). How thick is the shell if the average density of the spherical object is exactly 0.5 g/cm3 ? Assume there is a vacuum in the hollow interior of the shell. ...

**math**

We fire a missile from ground level at 1750 ft/sec. at launch angle of 10 degrees. h(t) =-16t^2 + vot +h a. find a function for height as a function b. find a function for distance from launch point as a function of time. c. when will the missile reach max height? d. What is ...

**chemistry**

The boiling point of diethyl ether, CH3CH2OCH2CH3, is 34.500 °C at 1 atmosphere. Kb(diethyl ether) = 2.02 °C/m In a laboratory experiment, students synthesized a new compound and found that when 13.85 grams of the compound were dissolved in 283.2 grams of diethyl ether...

**MATH**

The shop sold 264 inflatable rafts in 24 days. What was the average number of rafts sold each day?

**MATH**

The shop sold 264 inflatable rafts in 24 days. What was the average number of rafts sold each day?

**World history**

what freedoms were the people of Napoleon's day willing to sacrifice

**6TH GRADE MATH**

I think it has something to do with proportion

**physics**

450.4 m/s

**physics**

4 m/s

**algebra**

I having serious problems trying to solve this equation please help me find the product matrix for this input-output and demand matrices A= [ 0.1 0.03] D= [5] [ 0.07 0.6] [10]

**math**

Wrong!!The question is how many boys CURRENTLY attend the school. and that is 2x=108

**chemistry**

A 7.00 g sample of KCl is dissolved in 81.0 mL of water. The resulting solution is then added to 28.0 mL of a 0.790 M CaCl2(aq) solution. Assuming that the volumes are additive, calculate the concentrations of each ion present in the final solution.

**algerbra**

how do i solve with substitution?

**algerbra**

3x-2y=8 2x=2y=22 How i solve with substitution?

**algebra**

-3x-5y=-6 6x+5y=-34 how do i solve this using elimination?

**chemistry**

Buttermilk has 9 grams of protein and 12 grams of carbohydrate per cup (237ml). Estimate the concentration in mol/L of protein using the fact that the average protein is 300 amino acids long and the average amino acid has a mass of 110 amu

**Chemistry**

39

**IWU**

You are considering buying 27 silver coins that look alike, but you have been told that one of the coins is a lightweight counterfeit. Find the least number of weighings on a balance scale that you can use to be certain you have found the counterfeit coin. Can you explain the ...

**advance functions**

Determine the Interval notation and Inequality notation of the absolute value notation: abs(x)>-5

**Advance Functions**

Solve: 12+4|6x−1|<4 5−6|x+7|less than or equal to 17 ...can you please explain to me.. i know that it's like solving algebraically but one of them has no solution..

**MHF4U**

Solve: 12+4|6x−1|<4 5−6|x+7|less than or equal to 17 ...can you please explain to me.. i know that it's like solving algebraically but one of them has no solution..

**English 4**

The very fact that a woman's face is being compared to a garden throughout the entire poem.

**College Math**

I guess that the number of men and women doesn't matter so they're just 35 all. My answer is 35P4 + 31C6. . I used permutations for the pres~sec b'cse they have diff roles, not like the advisory committee. . Email me at ust008332@gmail if you found a better answer.

**home economics**

As part of the nation’s recovery from the Great Depression of the 1930s, the banking system was reformed in which of the following ways? A. The government paid off loans for large corporations. B. The Federal Reserve Banks were closed. C. Banks were deregulated by the ...

**Math**

Calculate the monthly finance charge for the following credit card transaction. Assume that it takes 10 days for a payment to be received and recorded and that the month is 30 days long. Assume 365 days in a year. (Round your answer to the nearest cent.) $3,000 balance, 21% ...

**Geometry**

The base of the prism is a rectangle with sides 13 m and 5 m in length. Find the lateral surface and surface area of the given prism.

**Anthropology**

Ethnographic methods are to ethnological methods as: (Points : 1) the humanities are to the sciences. fieldwork is to laboratory experiments. description is to comparison. nature is to culture.

**Physics**

the charges an coodinates of two points charges located in x-y palne are : q1=+3*10^-6 C ; x=+3.5 cm . y=+0,5 cm and q2=-4*10^ -6 C; x= - 2 cm y=+1.5 cm . (a)Find the electric potential at the origin(b)How much work must be done to locate these charges at their given positions...

**Physics**

Consider a point charge with q= 1.5*10^-8 C. (a) what is the radius of an equpotential surface having a potential of 30 V?(b)Are surfaces whose potential differ by a constant amount (1,0 V) evenly spaced in radius?

**Physics**

A thin condicting spherical shell of outer radius 20cm carries a charge of +3 muC. Sketch (a) magnitude of the electric field E and (b) potential V versus the distance r from the center of the shell.

**Physics**

a small sphere whose m mass is 1.0 mg carries a charge q of 2.0*10^(-8)C. It hangs from a silk thread that makes an angle of 30 degrees with a large charged nonconducting sheet as in figure. Calculate the uniform charge density σ for the sheet

**criminal law**

•Should the United States combine all the police agencies into one national police organization? Why or why not? •If you must consolidate the police, would you have to do the same to the criminal justice system? How would you create and establish such a police ...

**mats**

Factorise into prime factors: 2m^20-1/8

**Physics4**

2. At the point of fission, a nucleus of 235U that has 92 protons is divided into two smaller spheres, each of which has 46 protons and a radius of 5.9 × 10^-15 m. What is the magnitude of the repulsive force pushing these two spheres apart? The value of the Coulomb ...

**Physics3**

Two charged particles of equal magnitude (+Q and +Q) are ﬁxed at opposite corners of a square that lies in a plane (see ﬁgure below). A test charge −q is placed at a third corner. If F is the magnitude of the force on the test charge due to only one of the ...

**Physics2**

A particle of mass 47 g and charge 54 C is released from rest when it is 13 cm from a second particle of charge −15 C. Determine the magnitude of the initial acceleration of the 47 g particle. Answer in units of m/s2

**Physics1**

Four point charges are placed at the four corners of a square. Each side of the square has a length L. Find the magnitude of the electric force onq2 due to all three charges q1, q3 and q4 for L = 1 m and all q = 1.55 C. Answer in units of N

**electrostatic physics**

drwls, all four q is 1.55C

**electrostatic physics**

Four point charges are placed at the four corners of a square. Each side of the square has a length L. Find the magnitude of the electric force on q2 due to all three charges q1, q3 and q4 for L = 1 m and q = 1.55 C. Answer in units of N

**electrostatic physics**

A particle of mass 47 g and charge 54 C is released from rest when it is 13 cm from a second particle of charge −15 C. Determine the magnitude of the initial acceleration of the 47 g particle. Answer in units of m/s2

**electrostatic physics**

I thought it was 8 but im wrong

**electrostatic physics**

Two charged particles of equal magnitude (+Q and +Q) are ﬁxed at opposite corners of a square that lies in a plane (see ﬁgure below). A test charge −q is placed at a third corner. If F is the magnitude of the force on the test charge due to only one of the ...

**electrostatic physics**

An uncharged molecule of DNA (deoxyribonucleic acid) is 2.15 m long. The ends of the molecule become singly ionized so that there is a charge of −1.6 × 10^−19C on one end and +1.6 × 10^−19C on the other. The helical molecule acts like a ...

**electrostatic physics**

2. At the point of fission, a nucleus of 235U that has 92 protons is divided into two smaller spheres, each of which has 46 protons and a radius of 5.9 × 10^-15 m. What is the magnitude of the repulsive force pushing these two spheres apart? The value of the Coulomb ...

**trig**

a tree growing on a hillside casts a 102-foot shadow straight down the hill. Find the vertical height of the tree if, relative to the horizontal, the hill slopes 15.0 degrees and the angle of elevation of the sun is 62.0 degrees.

**Physics**

A lawn mower has a flat, rod-shaped steel blade that rotates about its center. The mass of the blade is 0.65kg and its length is 0.55m. What is the rotational energy of the blade at its operating angular speed of 3450 rpm? If all of the rotational kinetic energy of the blade ...

**Physics**

A wheel of radius R starts from rest and accelerates with a constant angular acceleration alpha about a fixed axis. At what time t, will the centripetal and tangential accelerations of a point on the rim have the same magnitude?

**Physics**

A centrifuge is a common laboratory instrument that separates components of differing densities in solution. This is accomplished by spinning a sample around in a circle with a large angular speed. Suppose that after a centrifuge in a medical laboratory is turned off, it ...

**Grammar**

Thanks! (:

**Grammar**

In the sentence "Let's walk around." Walk is the noun or the verb? And What is "Let's"?

**Math %**

Please advise how do I get the Regular % and the Cummulative % I just need one example other wise I will lose what's left of my mind. Defect Description Qty Improperly Sized 258 Bad Seam 153 Missing Buttons 67 Fabric Flaw 22 Total 500

**Statistics**

Please advise how do I get the Regular % and the Cummulative % I just need one example other wise I will lose what's left of my mind. Defect Description Qty Improperly Sized 258 Bad Seam 153 Missing Buttons 67 Fabric Flaw 22 500

**Business Math**

Please confirm if I did this correctly: What is the Principal? Principal $21250 X 10% 2,125 What is the total amount paid by the consumer? 2,125 x 3.5 years 7,437.5 +21,250.0 28,687.50

**chemistry**

how would you make one gram potassium chloride with barium chloride and potassium carbonate

**chemistry**

how would you make one gram potassium chloride with barium chloride and potassium carbonate

**college math**

Find the distance of the shotcut and the distance of the long way for two locations. find the number of seconds saved ( 2.1 and 5.8) Approximate the are of the affected region (24 and 248 Sq Ft). find the average amount of oxgen saved per second saved (10.8 and 110.6 KG of ...

**college physics**

A diver runs horizontally with a speed of 0.759 m/s off a platform that is 10.0 m above the water. What is his speed just before striking the water?

**physics**

An airplane with a speed of 94.9 m/s is climbing upward at an angle of 63.2 ° with respect to the horizontal. When the plane's altitude is 743 m, the pilot releases a package. (a) Calculate the distance along the ground, measured from a point directly beneath the point...

**college physics**

loft the ball with an initial speed of 15.0 m/s at an angle of 50.0° the horizontal. At this instant your opponent is 10.0 m away from the ball. He begins moving away from you 0.38 s later, hoping to reach the ball and hit it back at the moment that it is 2.10 m above its...

**college physic**

a rifle that has been ‘sighted in' for a 91.4-meter target. If the muzzle speed of the bullet is v0 = 328 m/s, there are the two possible angles è1 and è2 between the rifle barrel and the horizontal such that the bullet will hit the target. One of these ...

**college physics**

An airplane is flying with a velocity of 240 m/s at an angle of 30.0° with the horizontal, as the drawing shows. When the altitude of the plane is 2.4 km, a flare is released from the plane. The flare hits the target on the ground. What is the angle è?

**Chemistry**

For the weak acid HX, what is the pH of a 0.10 M solution if the acid is 4.0% ionized?

**chemistry**

Calculate the pH in a 0.00500 solution of NaOH.

**Maths**

how do you factorise 2x-y-ysqaured? thanks

**Math**

If your neighbor's house is 2/8 smaller than you house and the volume dimensions of your house are 13, 26 and 130 sq ft, what is the volume of your neighbor's house

**physics**

a 150 grain .30-06 bullet has a mass of 0.01 kg and a muzzle velocity of 900 m/s. If it takes 1 ms(millisecond) to travel down the barrel, what is the average force acting on the bullet?

**Stastics**

no, you have to use a t value. you did the problem wrong.

**physics**

The water skier in the figure is at an angle of 35degree with respect to the center line of the boat, and is being pulled at a constant speed of 15m/s . 1)If the tension in the tow rope is 90.0N, how much work does the rope do on the skier in 30.0s ? 2)How much work does the ...

**physics**

The water skier in the figure is at an angle of 35degree with respect to the center line of the boat, and is being pulled at a constant speed of 15m/s . 1)If the tension in the tow rope is 90.0 , how much work does the rope do on the skier in 30.0 ? 2)How much work does the ...

**Physics**

Given: 90m skid mark .50 coefficient of friction between the tires and skid mark How fast is the car moving when the brakes initially applied?

**Physics**

it says to use conservation of energy we know conservation of energy when not dealing with heat is u+k=u+k where u is the potential energy and k is you kinetic energy. potential energy is mass x gravity x height. kinetic energy is (1/2)(mass)(velocity)^2. from there you get ...

**Physics**

Vw+b = Vb x sqrt[Mb/(Mb+Mw)] I've derived it from 0.5xMbx(Vb^2) = 0.5x(Mb+w)x(Vw+b)^2

**chemistry**

part B. would you expect the emissions to vary if metal flourides were used rather than metal chlorides?

**chem**

why do different compound have different colours in their visible emissions?

**physics**

Vector A has a magnitude of 23 units and points in the positive y-direction. When vector B is added to A, the resultant vector A+B points in the negative y-direction with a magnitude of 15 units. Find the magnitude of B?

**physics**

An airplane flies 200 km due west from city A to city B and then 305 km in the direction of 30.0° north of west from city B to city C. (a) In straight-line distance, how far is city C from city A? ___km (b) Relative to city A, in what direction is city C? ___° north of...

**Physics**

A brick is thrown upward from the top of a building at an angle of 30° to the horizontal and with an initial speed of 11 m/s. If the brick is in flight for 3.2 s, how tall is the building? ___m

**physics**

A jet plane lands with a speed of 101 m/s and can accelerate at a maximum rate of -4.60 m/s2 as it comes to rest. (a) From the instant the plane touches the runway, what is the minimum time needed before it can come to rest? ___s b)What is the actual minimum distance needed to...

**Physics (Oscillation)**

20cm 94.2 17.8

**chemistry,math**

One liter of approximetely 0.25N HNO3 has been prepared. Upon titration it was found that 5.0 ml of the acid required 11.0 ml of 0.10N NaOH for neutrality. How much concetrated HNO3 at 15.8N must be added to one liter to make it exactly 0.25N?

**math,chemistry**

How much water should be added to 1 liter of 0.12N HCl to prepare exactly 0.1N HCl?

**math,science,lab**

One liter of approximetely 0.25N HNO3 has been prepared. Upon titration it was found that 5.0 ml of the acid required 11.0 ml of 0.10N NaOH for neutrality. How much concetrated HNO3 at 15.8N must be added to one liter to make it exactly 0.25N?

**statistics**

a random sample of 100 college students is taken from the student body of a large university. assume that a population mean of 20 hours and a population standard deviation of 15 hours describes the weekly study estimates for the entire student body. About 68 percent of the ...

**Society**

are these countries that are growing in population though, urbanization? are these two the same city? Ho Chi Minh City (Saigon),

**Society**

What do you think a good third world city or a major city in a poor developing country would be a good one to write an urbanization report and trends on? I have to have a major city in the country? I just want advice if anyone knows what one would be good to research and write...

**chemistry**

What is the pH of the solution created by combining 12.90 mL of the 0.10 M NaOH with 8.00 mL of the 0.10 M HC2H3O2?

**5th grade**

Is there hidden cost with pulley systems that reduce effort?

**trig**

b=a(tanB) where a is your altitude, B is your angle of depression and b is your distance to airport. b=30,000(tan(72)) b=92,330.51

**Physical Science**

34000 s

**physics**

worked thanks...