# Posts by bobpursley

Total # Posts: 45,286

**Algebra, Trig**

y=10sin(x-45°)+20 y is the height, so 15-20=10sin(x-45) sin(x-45)= -.5 sinTheta= -.5 theta= 330deg, or 210 but x-45=210, or 330 so x= 255 or 375 (15 deg)

**Algebra help!!**

what is y-4=sqrt(34x^3) http://www.themathpage.com/aprecalc/translation.htm

**connections academy**

Learning is no more regurgitating answers than digestion is regurgitating what you ate. Learning is processing, making connections, and exploring what one does not know. I am very afraid many HomeSchool families do not understand, nor appreciate this. Homeschool is an ...

**Science**

I wonder what a normal solid is. That is not a scientific classification. I wonder if the asker meant "metals", as all but 2 are characteristics of metals.

**Chemistry**

I agree.

**Texas State History**

Hint, hint: my girl scouts paddle (canoes and kayaks) down the San Marcos River to its mouth at the xxxxx river. Each Summer that is a great voyage of adventure. There is one waterfall they have to carry their boats around down the hill.

**steve**

here is the original post, as I think. I have no idea what is being asked here. https://www.jiskha.com/display.cgi?id=1508332099

**Physics**

gpe: mass*g*height KE: 1/2 mass*velocity^2 total ME: add the above

**Chemistry**

true

**ochem**

<<In combination, the equatorial bulge and the effects of the surface centrifugal force due to rotation mean that sea-level effective gravity increases from about 9.780 m/s2 at the Equator to about 9.832 m/s2 at the poles, so an object will weigh about 0.5% more at the ...

**Physics**

it is at the peak at 6.5/2 seconds... and the velocity at the top is zero.. so consider it going down... hf=hi+vi*t-1/2 g t^2 0=hi+0*t-1/2 g t^2 you know g, solve for hi

**Physics**

see other post

**Physics**

https://www.jiskha.com/display.cgi?id=1508286455 draw the triangle, verify the distances.

**Physics**

ok, now reading it like a lawyer, it dropped down 1.8 displacement= sqrt(1.8^2 + 2.7^2) angle= arctan(1.8/2.7)

**Physics**

https://www.jiskha.com/display.cgi?id=1508283496 change the 2.7 to 1.8....

**History**

It appears you mistyped the choices, only three are there, that I can see.

**Physics**

thanks, professor, I skipped over the height of the flower.

**Physics**

a. sqrt(2.7^2+5.3^2) b. what is arc tan 2.7/5.3

**physics**

hf=1/2 g t^2 t= sqrt (2h/g)

**Math-Scale Factors**

wouldn't it make a mirror image (reflection of the graph?

**physics**

force*time=mass*change of velocity change of velocity considers direction, of course, change of velocity=vf-vi=12-(-16)=28m/s solve for average force.

**Physics**

3km/hr=3km/hr*1hr/3600sec*1000m/1km=0.83m/s force*time=mass*changevelociyt force= 5000*.83/.64 N = ???

**5th grade Science**

Heat is stored in the matter and its motion. The more matter, or the more motion, the more energy it has.

**Physics**

only the perpendicular velocity changes. how is the angle measured, to the side, or to the normal? I will assume to the side. change velocity perpendicular to rail=2*15cos60 momentum change=.2*changevelocity

**Vet Science**

The tuber ischii (pin bone) is the most caudal part. One pin bone is located on either side of the vulva. Width between the pins does not correlate with kidding ease, as these bones are immobile. So for a normal goat, there are two sides.

**Physics**

vertical: time in air. hf=hi+3*sin39*t-4.9t^2 hf,hi=0, find time t, time in air.

**Physics**

let a be the distance from a to the ship1 and b be the distance from a to the ship2 now c is the distance between a and b. c^2=a^2+b^2 let time t be the time after 8AM, so t=0 is 8 am, 9:30 is 1.5 I am going to use speed 7, you can do it yourself with speed 7.5 c^2=(7*t )^2...

**Science**

enzymes are catalysts for chemical reactions, allowing pathways which require less energy to get the reactions started.

**Chemistry**

well, if the temp rose, the reaction was exothermic (negative sign). heat=-23.03*C*(53.67-15.21)

**Chemistry**

obviously, A has more stored heat.

**History**

Seldom do governments (the church was a govenment in the middle ages) operate in a vacumn away from technology. Johannes Gutenberg's work in the printing press began in approximately 1436 when he partnered with Andreas Dritzehen—a man he had previously instructed in ...

**Algebra HELP**

I have no idea what the teacher has in mind, in my mind, it is not like FOIL. http://www.montereyinstitute.org/courses/DevelopmentalMath/COURSE_TEXT2_RESOURCE/U16_L2_T3_text_final.html

**More physics help**

avg linear velocity=12/3.25 m/s tangential velocity=angvelocity*radius avgangvelociyt= avglinearvelociy/radius for info, check avg linear velocity above with avg of 7.38/2 = 3.69 m/s above, 12/3.25=3.69 m/s

**BCom**

https://www.roselladb.com/insurance-risk-analysis.htm

**ZagaZig University**

If this is on Earth, then the force of gravity is .5kg*9.8N/kg=4.9Newtons forceconstant=force/stretchinMeters =4.9/.04 N/m

**Physics Help**

b could help, but the rotational inertia involved is trivial, it hardly could be measured on linear acceleration difference.

**Ethics**

https://www.bloomberg.com/features/2016-walmart-crime/ Do you see some ethical conflicts in this? You can easily google the issue of "stealing" from the rich.

**Texas History**

Nowadays, they come from California to TExas, and spend days trying to find holistic healers when they are sick. That dog doesn't hunt in Texas

**Science**

for most plants, true

**Periodic Table**

Nope, think about D and you know why A is wrong.

**Periodic Table**

D is the best asnwer.

**History**

Dear Santa: Give me all I want, so that I dont have to work hard like the smart kids do.

**Math**

Graph the first two as lines y= -2x+300 and y=-x+300 then graph the positive x axis, and the positive y axis. Now the region within that four sided figure is the allowed region for x and y. However, we have a nice theorem which states that maximum and minimum of any objective ...

**Math**

1Csugar=.24L or 1Csugar/.24L=1 or .24L/1Csugar=1 these are so-called unit conversion factors, so you can use them in multiplying (you dont change an equation if you multiply by 1) 1.25Csugar*(.24L/1Csugar)=1.25*.24 Liter

**Thermodynamics**

change units to either cal,or joule, then subtract.

**Physics**

What is 3mL^2

**earth science**

is there a question here?

**Chem**

The half-life of a reaction is the time required for the reactant concentration to decrease to one-half its initial value. The half-life of a first-order reaction is a constant that is related to the rate constant for the reaction: t1/2 = 0.693/k. rate constant= .693/48

**physics**

two-fifths speed, that means KE is 4/25 of all the energy. find her speed if no friction mgh=1/2 mv^2 v= sqrt(2gh) her speed is 2/5 of this , or energy is 4/25 of original energy. friction energy=mgh(4/25) mu*cos20*mg*h/sin20=mgh(4/25) mu=tan20*(4/25) check my work

**Math ( lim inf question)**

is n an integer? Or any value?

**Physics**

You forgot distance on the friction component. Energy= friction*distance

**Physics**

you could do it energy. initial energy:1/2 m v^2 that initial energy is converted to Friction and PE. friction:.3*mg*cos37*8 PE: mg*8*sin37 set initial energy=friction+PE second part. Initial PE=mg*8*sin37 friction=.3mg*cos37 final KE=1/2 m v^2 finalKE=Initial PE-friction ...

**physics**

the change of velocity is 90m/s impulse=massball*90

**A - G requirements**

OK, you last year "messed up". I assume that means you flunked most of your courses. Now you are in your sophmore year of HS, and you want to get with it. What I suggest is you find out what is going on. Did you and parents have a conference last year with your ...

**biology**

https://www.cellsalive.com/cell_cycle.htm only mRNA has been produced. The DNA has not separated into haploid sequences in G1

**Physics**

wondering what temperature this occurs at. dl/l=(force/area)/young's modulus force=mass*g=youngMod*area*dl/l dl/l= .0211 area=PI(.0027/2)^2 g= 9.8N/kg mass(in kg)=youngMod*area*dl/l*1/9.8 Young mod is about 200E9 N/m^2 about, but it depends on temperature.

**math**

slope 6 y=6x+b 3=6*5+b b= 3-30 I get a negative intercept.

**Physics**

a r=9/1.5 b. power=9*1.5

**Physics**

Aren't there postive charges in the nail that holds them near?

**physics**

change tons to kg.

**physics**

force down;mg*costheta force=ma. solve for acceleration a. then vf=a*time

**Slit width in double slit experiment**

I can't see this photograph, but it is very sililar to this; http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/dslit.html#c1 this resource probably will be helpful http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/slits.html#c1

**Genetics**

remember this applies to HUMANS, not to all other birds, bees, bugs, and etc.

**Biology**

ss=short ll=long sl=short-lon slxsl=ss, sl, sl,llTwo short-longs mate and produce some shorts, some longs and some short-longs co dominance

**Biology**

sounds much like incomplete dominance. RW=pink

**Wavelength of a light**

are you certain the distance from the center to the first minium is .04m?

**History**

Desiderius Erasmus: “If the Gospel were truly preached, the Christian people would be spared many wars.”

**History**

as I read the 95, he never mentioned a,b, or c. Now on indulgence, he did offer criticism on indulgence, especially how it was applied, and the bad effects it had on penance, but I cannot find that he ever attacked the idea of indulgences themselves, and, it can be noted, ...

**Biology**

BBxgg=Bg,Bg,Bg,Bg first generation BgxBg=BB,Bg,Bg,gg second generations Complete dominance is a form of dominance in heterozygous condition wherein the allele that is regarded as dominant completely masks the effect of the allele that is recessive. For instance, an individual ...

**Chem**

Good, however, something is missing here.

**Math**

yes, A

**math**

the value of x determines the truth of equation 1. Open Sentence: an equation or inequality containing one or more variables in which its truth or falsehood depends upon the values assumed by the variables in a particular instance, as the equation x + 3 = 8.

**Connexus**

Thanks.

**Chemistry**

go thru this similar problem (answer is on second page). Then try this one, I will be happy to check your work. http://www.wou.edu/las/physci/poston/ch221/pdf/Limiting-Reagent-Problems-Key.pdf

**physics**

force*distance=1/2 m v^2 force=.5*30*100/50 N

**mte**

sloper= dy/dx=(-5-2)/(-5-6)=7/11

**History**

I agree with 2), mainly because of the invention of the printing press, and demand for more books, and more information.

**math**

C-250=15n n=C/15-250/15

**Biology**

you want 5ml of 20mg/ml in buffer. you are diluting the solution 250/20 times, or 12.5 times. So you need one part original protein sample, 11.5 parts buffer. What is each part? 1 part=5.0ml/12.5=4ml 11.5 parts= 46ml

**math**

No, you are in serious trouble. You have several misconceptions about adding fractions. https://video.search.yahoo.com/search/video;_ylt=AwrBT0fQl99ZxMsA5W9XNyoA;_ylu=X3oDMTEyNWNiaW4yBGNvbG8DYmYxBHBvcwMxBHZ0aWQDQjI5NDRfMQRzZWMDc2M-?p=adding+%2F+subtracting+fractions&fr=mcafee#...

**Physics**

mgh/60sec=1hp(.9)(746watts/hp) mass= 60sec/(9.8N*30m)*747n-m/sec)*.9 =137

**Physics**

if one measures displacement in the vertical, and velocity in the direction it is going, then at the bottom position, vertical displacement is zero, and velocity is maximum.

**physics**

One wonders what the question is.

**science biology quick question**

Amazing.

**science biology quick question**

E is the better choice, because it is the standard "science" word for prediction or guess.

**Da Fash**

Knock it off. We left all that silliness behind in elementary school. If you can't, we will.

**physics**

conservation of momentum: set up the equation in x,y directions, so you have two conservation of momentum equations. Notice two unknowns, direction and velocity of second ball. That should do it, two unknowns, two equations, and a bit of algebra (and basic trig). Here is a ...

**Science I Need Help**

A is the best answer.

**organic chemistry -urgent**

DrBob, you missed this class. https://tse2.mm.bing.net/th?id=OIP.5x-xhxBm0LuLMmKKcZ0SQgDdEZ&pid=15.1&P=0&w=300&h=300 available on Amazon.

**biology**

toni...concentration hyper...?

**Maths**

s=k(4t^2+8t+9) v=8kt+8 a=8k

**Physics**

Nope, Not C. see the solution here, number 16: http://prernaclasses.com/AIEEE2011PhyQuestionsSolutions.pdf

**Science-Chemistry**

distance=speedofLight*time watch your units, speed of light (distance/time) needs to be in the same units as time,or you need to convert those.

**Chemistry**

see other post

**physics inertia**

For a point-like mass, the moment of inertia about some axis is given by m r^2 For an extended rigid body, the moment of inertia is just the sum of all the small pieces of mass multiplied by the square of their distances from the axis in question. that does not total 4mr^2 ...

**Physics**

horizontal motion: 46.50=Vi*cos38*time verticalmotion hf=hi+vi*sin38*t-1/2 9.8 t^2 hf=hi=0 so have two equations, two unknowns (time t, and vi) solve for time t in the first eequation, put that into the second equation and solve for vi a bit of algebra is required.

**Algebra**

B>=320 168+46+33+Final>=320 final>=320-247 final>=73 so she needs a 73 or better.

**Math**

Hmmmm. Something is missing here.

**TX History**

and, in the fashion of inserting today's mores into history, Stephen F. Austin helped ensure the introduction of slavery into Texas despite the attempts of the Mexican government to ban the institution.

**Physics**

flight time is determined by the falling height: the building did not change height.