# Posts by Hank

Total # Posts: 50

Maths
Thanks Reiny, appreciate it

Maths
The distance between 2 towns is 330km. A train travels between these two towns and returns on the same day. On the return journey, the train left late and so the driver decided to drive the train 5km/h fasterthan its inward journey, and it took 30 minutes less time to return. ...

basic science
Soil, air, light

Maths
Couldn't have said it better myself

Math
Mr.Anders wants to put a fence around his back yard.his backyard is rectangular. The lengths of the sides are 75 yards,45 yards,75 yards,and 45 yards.How much fencing will Mr.Anders need?

chem
a) Silver iodide(s) is formed by the following reaction: Ag (aq) + I (aq) --> AgI (s) The Ksp for AgI = 1.8 x 10^-10 Describe, using the chemical reaction, the mathematical formula for these ions. Assuming these ion concentrations are equal, what would the molarity be for ...

cheMistry
a) Silver iodide(s) is formed by the following reaction: Ag (aq) + I (aq) --> AgI (s) The Ksp for AgI = 1.8 x 10^-10 Describe, using the chemical reaction, the mathematical formula for these ions. Assuming these ion concentrations are equal, what would the molarity be for ...

Calculus
Can someone show how to solve this problem Two vertical towers of heights 60 ft and 80 ft stand on level ground, with their bases 100 ft apart. A cable that is stretched from the top of one pole to some point on the ground between the poles, and then to the top of the other ...

nutrition
If your dinner has no vegetables, you should eat a cereal containing fiber at breakfast

Statistics
nah

Chemistry
Calculate the S(univ) for the following phase change at 25 deg celcius. The boiling point of heptane is 98.0 Celcius and has a Delta Hvap= +21.6kj/mol. C7H16(l)--> C7H16(g) Delta S= +79.0j/k I know that the equation is Delta Suniv= DSsys + DSsurr PLEASE SHOW ME HOW TO DO IT...

Chemistry
Calculate Ecell for reaction for the given info below.. O2(g)+2H2O(l)+4Ag(s)--> 4OH-(aq)+4Ag+(aq Ag+(aq)+ 1e ---> Ag(s) Ered= 0.80v O2(g)+2H2O(l) + 4e ---> 4OH- Ered= 0.40v My confusion is I have done problems similar to this when the Ered was negatives, but two ...

Chemistry
I.e Pb(NO3)2+NaI==> PbI2 + NaNO3 I know NO3 will dissolve in water, but if I didn't know if PbI2 was solid or aqueous, how would i figure that out? and Al(3+)+ 6F- ===> [AlF6]^3- (aq)

Chemistry
If I was taking an exam and I had no solubility rules given...

Chemistry
Equilibria* (complex ions Equilibria)

Chemistry
If I had a question about complex ions and the problem had a "mixture" of two compounds, how would I know if one of the products formed is going to be a solid or liquid? I know there are solubility rules, but is there something else you can use to tell?

Chemistry
79.0J/K- 21600/298k= +6.5

Chemistry
Could I just use the formula DSuniv= DSsys- (DHsys/T)

Chemistry
I did as you said and I got the wrong answer. the correct asnwer is supposed to be +6.5, and I am getting -25.8.. Can you just show me how to do it with numbers and steps. I am just more confused now.

Chemistry
DrBob222

Chemistry
So since Delta S= +79.0J/K is Delta S equal to Delta Ssys? I don't get the relationship of Delta S and sys and surr with delta S (entropy) that would make it become +79.0J/K DSsys and then DSurrs= (-21600J/mol*1mol)/298K= -72.5J/K Suniv= +79.0J/K+-72.5J/K= +6.5

Chemistry
Calculate the S(univ) for the following phase change at 25 deg celcius. The boiling point of heptane is 98.0 Celcius and has a Delta Hvap= +21.6kj/mol. C7H16(l)--> C7H16(g) Delta S= +79.0j/k I know that the equation is Delta Suniv= DSsys + DSsurr but for DSurr= -0.216J/371k...

Math

Physics
Two charged particle are fixed on the x-axis 11 cm apart. The one on the left has a net charge of +25uc and the one on the right has a net charge of -11uc. What is the magnitude of the electric field 10 cm to the right of the negative charge? How do you solve this problem? ...

trig
Find all the solutions from [0, 2pi] cot^2x+csc=x

gen physics
An iron (ƒâ = 7860 kg/m3) cube measuring 15.4 cm on a side is suspended from a wire. Find the tension in the wire when the block is completely submerged in water (ƒâ = 1000 kg/m3).

physics
A hydraulic jack has an input piston with a diameter of 1.00 cm, and an output piston with a diameter of 6.00 cm. What weight (in N) can be lifted when a force of 45.8 N is applied to the input piston? Answer is 1650 N but I need someone walk me through the steps please.

physics
A tank contains mercury, whose density is 13 600 kg/m3. Find the force exerted by the mercury on a circular plug at the bottom of the tank. The plug has a diameter of 2.54 cm, and is located 37.6 cm below the surface of the mercury. The answer is 25.4 N but I don't know ...

Physics
An object (m=2.85 kg) is attached to a disk-shaped pulley. The diameter of the pulley is 0.242 and its weight is 7.272 N. Suppose the object is allowed to fall (a) What is its linear acceleration? (b) What is the angular acceleration of the pulley? (c) How far does the bucket ...

math
The scale factor for two similar retangles is 3. If the area of the smaller rectangle is 8m^2, what is the area of the larger rectangle.

Math-factoring
factor 5m^2-m-20

Math
Find relative extrema of f(x)=x^3-3x^2+4

Calculus
Given y=(x^2+2)sqrt(x^3-8x) Find dy/dx

Calculus
a)Find dy/x where y=tan(4=x^3)^4? B) Find relative extrema of f(x)=x^3-3x^2+4

chemistry
When a 0.5725 g sample of Lysol was titrated with 0.100 M NaOH, an endpoint was obtained at 15.00 mL. What is the percent of HCl in the Lysol sample?

Calculus
find the area under the curve y = x^2 + x from the origin to the line x = 3

Calculus
Find the derivative of y = 3x+2/x+1

calculus
When the area in square units of an expanding circle is increasing twice as fast as its radius in linear units, the radius is (a) 1/4pi (b) 1/4 (c) 1/pi (d) 1 (e) pi

Finite Math
Time-share sales provide an opportunity for vacationers to own a resort condo for 1 week (or more) each year forever. The owners may use their week at their own condo or trade the week and vacation elsewhere. Timeshare vacation sales usually require payment in full or ...

Graphing
I am plotting V/Vo vs 1/[C] and am asked to extrapolate to infinite concentration to obtain b/Vo, the intercept. How would I go about doing this?

chemistry
9.10-5.41=3.69 18.0152/3.69=??

chemistry
well i got 3.69% but that doesnt look right

chemistry
is the answer 40.5% or 59.5% ?

chemistry
a hydrated salt is a solid that includes water molecules within its crystal structure. a student heated a 9.10-gram sample of a hydrated salt to a constant mass of 5.41 grams. what percent by mass of water did the salt contain?

Math: Calculus
Does it mean, 0.5*10*70=350 m?

Cultural Anthropology
I'm having trouble coming up with a topic that'll expand to 10 pages for my final research project. I have to choose a culture and an issue within that culture. Any ideas will be appreciated! Thanks!

Statistics
A gas station manager thinks the average motorist changes their oil less than the recommended two times per year. In a survey 15 car owners were asked how many times they changed their oil in the past year. Here are the results: 1 1 2 1 2 2 0 1 0 1 2 3 1 3 0 The value of the ...

chemistry
the ans, is 45.6

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