Posts by Kayla
Total # Posts: 1,528
Math
What is the best estimate for the product of 289 and 7
Precalculus 11
I have looked at this for 2 days & not understood but I think I get it... so you multiplied the top & bottom by -1 which made the top 5-2a but then you factored out the negative making it -(2a-5)/(5a-2) is that correct? Thank you so much for your help :)
Precalculus 11
(6a^2-15a)/(6a-15a^2) (3a(2a-5))/(3a(2-5a)) Multiply top & bottom by -1 -(5-2a)/(5a-2) is that correct? I have an answer here that's -(2a-5)/(5a-2) but I don't understand how to get there... Thanks :)
Precalculus 11
Ok, that makes sense :) thank you very much
Precalculus 11
If when simplifying 2 rational expressions you got: (-2(x-3))/2-x would you multiply the top & bottom by -1? Thanks!! :)?
Precalculus 11
Ok, thank you :)
Precalculus 11
When subtracting 1 rational expression from another, when I'm multiplying the top & bottom of the first term by the denominator in the second term is that number automatically negative because the whole term is being subtracted? ex: (8a-3b)/7a - (2a+5b)/4b is the 4b ...
Precalculus 11
That makes total sense, thank you very much :)
Precalculus 11
but why is the +1 on the planes side of the equation when it was the train that took an hr longer? Thanks again :)
Precalculus 11
It takes an express train 1hr longer to travel 240km than it does for a small plane to travel the same distance. If the plane travels twice as fast as the train, how fast does the plane travel? This is an ex., they lay out online but I'm confused about how they've laid...
Precalculus 11
Sorry, I meant to say any unknown variable in the denominator :o
Precalculus 11
OK, so then any unknown variable is negative, correct? Thanks a bunch again :) I appreciate your help
Precalculus 11
Hello, I'm hoping someone can explain this to me: I'm ID-ing polynomials; -x^7-5x^4+(3/x)= not a polynomial .25x^3+3.9x^2-(x/3)= polynomial Why is 3/x not but x/3 is? Thanks a bunch! :)
Physics 11
You're right that does make sense, I got confused & mixed up t & t. if I switch them I get 1.1s. Thank you :) I appreciate your help
Physics 11
Devon speeds past Tamara in his space shuttle. In Tamara's frame of reference, the shuttle moves with a speed of 0.88c. Devon's radio is blaring out music with a beat that occurs every 0.50 seconds. How often does Tamara hear the beats? I'm getting 0.24 s but it&#...
Physics
A glow stick is placed 18.0 cm from a converging lens that has a focal length of 8.0 cm. Determine the location of the image using both a ray diagram & the lens equation. So I'm not sure if my diagram is perfectly accurate, they just said "at least 4 squares high"...
physics
Oh I get it! ok thank you :) I'll make note of that. I appreciate your help
physics
Good chocolate is designed to melt at 34°C. A chocolate bar, originally frozen to a temp of -115°C, has its thermal energy doubled. Will it melt? It's not like temperature, so if thermal energy is doubled that means heat is being added & therefore likely it will ...
Physics 11
Ok thank you :)
Physics 11
A rose is placed 15.0 cm in front of a convex mirror of focal length 10.0 cm. I assume f= -10cm bc it's convex correct? giving me (1/-10)-(1/15)=(1/di)? Thank you
Physics 11
I am & I can't get it to match up... They haven't given an exact height, they just say "at least 4 squares high" but between 4 squares & my cap I can't get it to that point.
Physics 11
Confused about the formula (1/-f)= (1/do)+(1/-di) For locating an image for a convex mirror. A rose is placed 15cm in front of a convex mirror of focal length 10cm. Determine the location of the image using the mirror equation. (1/-10)=(1/15)+(1/-di) -0.1=0.067 + (1/-di) -0....
Physics
Ok thank you :)
Physics
When a butterfly lands 12 cm from a concave mirror, it's image is 18 cm behind the mirror. Find the focal length 1/f=(1/do)-(1/di) 1/f=(1/12)-(1/18) 1/f=0.0833-0.0555 1/f=0.0277 f=36 I'm pretty confident w/ my math but as I understood, it's do-di if it's behind...
Physics 11
Thanks guys!!! 99% on my midterm mainly because of your help so your time is very much appreciated :) <3
Physics 11
Glycerine has an index of refraction of 1.47. What is the critical angle for a light ray traveling from: a)Glycerin into air b)Glycerin into water a) I know- n1=1.47 n2=1 angle of refraction=90 1.47(sin.anglei)= sin90 1.47(sin.anglei)=1 sin.anglei=0.6803 angle of incidence=42....
Physics 11-Ray Diagrams
I'm doing a ray diagram with an arrow leaning away from a plane mirror. The rays leading from the tip of the arrow to the image on the other side of the mirror lined up perfectly, however for the rays leading from the end of the arrow I can't seem to line it all up so ...
Physics 11
A student performs an experiment. On her desk, she directs a light ray at the flat surface of an unknown transparent material at an angle to the normal of 47 degrees. The light ray enters the material at an angle to the normal of 34 degrees. What is the index of refraction for...
Physics 11
I found a tutorial on youtube, he says just to do it to any point on the mirror unless otherwise specified. So I think I'm good :) Thanks a bunch!
Physics 11
Well that's the thing, I know what it looks like & they even went step by step in the lesson. I know that my reflected ray has to have the same angle to normal as my incident ray but I don't understand how I'm supposed to know what angle my incident ray is supposed...
Physics 11
I'm trying to draw a ray diagram (the image & mirror are already printed I just need to draw the rays) for a plane mirror. I understand the rules for the most part but I am confused about what angle I should be drawing the first ray from the tip of the arrow to the mirror...
math PLZ HELP
Which expression represents 12 times the number n? a: n+12 b: 12n c: n-12 d:n/12
Physics
Ok, that's a good idea, I struggle with the units sometimes so I should try & keep track anyways. Thanks again :)
Physics
Oh I mixed up my formula!! Thank you for catching that :) I hate stupid mistakes that I should know better than.
Physics
The speed of sound in a classroom is 343m/s. A) A tuning fork of frequency 512Hz is struck. What length of open air tube is required to create a resonant sound at the 1st harmonic? wavelength=v/f=343/512=0.67m L=.5wavelength=.5(.67)= 0.335m B) Fore the same tube, what tuning ...
Physics 11
Ok, that makes sense, thank you :)
Physics 11
As water waves from the ocean approach a shallow beach, their wavelengths become shorter. Explain why. v=fwavelength, frequency remains constant & velocity & wavelength decrease or increase w/ water depth. Is that a reasonable answer or are they looking for something else? ...
Physics 11
Ok excellent, thank you :)
Physics 11
The speed of water waves is 30cm/s in deep water & 15cm/s in shallow water. If the wavelength in deep water is 1.0cm, what is the wavelength in shallow water? (v2/v1)=(wavelength2/wavelength1) Therefore (15/30)=(wavelength2/1) - 15=30wavlength2 -Wavelength2=0.5cm/s A) Is that ...
Physics 11
Oh I get it!! Thank you very much :)
Physics 11
Waves travelling along a string have a wavelength of 2.4m. When the waves reach the fixed end of the string, they are reflected to produce a standing wave pattern. How far from the end are the first 2 antinodes? I know that each wavelength has 2 antinodes so each antinode has ...
Physics 11
Ok, I'm still a little bit confused. How do you know that it's half a wave length across? & in that case I'm saying .5 wavelength=L? & .25wavelength=each antinode? Thanks again :)
Physics 11
Waves traveling along a string have a wavelength of 2.4m. When the waves reach the fixed end of the string, they are reflected to produce a standing wave pattern. How far from the end are the first 2 antinodes? I feel like I don't have enough info here... I know that 1 ...
Physics 11
Thank you :)
Physics 11
A single wave pulse is sent along a thick rope that's tied to a thin rope, which in turn is attached to a wall. Reflection of the wave will occur at both points A (where the thick rope is attached to the thin rope) & point B (where the thin rope is attached to the wall) ...
Physics 11
Ok, thank you very much :)
Physics 11
I'm super confused about it because I asked my teacher how there could be 1 crest between a crest & trough she said "There's 1 crest between them so they are further apart" So I clarified that "that means there's 1 crest & 1 trough between? thanks&...
Physics 11
2 men are fishing from small boats located 36m apart. Waves pass through the water, & each man's boat bobs up & down 15 times in 75s. At a time when 1 boat is on a crest, the other 1 is in a trough, & there is 1 crest between the 2 boats. f=15/75=.2Hz Wavelength=36m V=f(...
Physics 11
V is constant bc electromagnetic waves are always V constant. How though can V be constant but there be more cycles occurring per second? Thanks again :)
Physics 11
You are creating waves in a rope by shaking your hand back & forth. W/out changing the distance your hand moves, you begin to shake it faster & faster. What happens to each of the following aspects of the wave? Amplitude remains the same as the distance shaken remained the ...
Physics 11
Thanks a ton!! :)
Physics 11
Thank you :) is c=300m/s a relatively constant value?
Physics 11
An FM radio station transmits radio signals that have a wavelength of 3.2m. Where would you have to adjust your tuner in order to pick up its music? Note: FM waves are measured in MHZ I have no idea where to go with this... Thank you :)
Physics 11
Oh... So essentially I'm saying 5-(-4) which is 5+4? that makes sense... Thank you :)
Physics 11
A student throws a .1kg ball at a wall. The ball hits the wall perpendicularly with a speed of 5m/s & then bounces back w/ a new speed of 4m/s. What impulse is given to the ball by the wall? I used deltaP= m deltaV so deltaP= .1*(-1) to get -.1N-s. I got it wrong! Can someone ...
Physics 11
A 1200Kg car travels at a constant speed of 26m/s for 5s up a 130m long hill. The total height of the hill is 27m & the friction force acting on the car is 2520N. What power was used by the car in traveling up the hill? I know that Fnet=o bc velocity is constant, therefore ...
Physics 11
Thank You!!! :)
Physics 11
If 2 vehicles are moving toward each other from opposite directions & are the same mass & velocity then momentum=0 correct? Because p=M1V1 - M1V1 Thanks!! :)
Physics 11
Ok, that's super helpful thank you very much!! :)
Physics 11
So does that mean if I have work against friction & acceleration I can use that one formula to cover both? :)
Physics 11
A 62kg cyclist changes the speed of a 12kg bicycle from 8.2m/s to 12.7m/s. Determine the work done. I've already answered & gotten this question correct, however it made me confused about the concept. I found Ek. & Ek to find change in Ek which was 3479.85. He did work ...
Physics 11
Ok, so then is it fair to say that when Fapp releases an object in the air or on a horizontal surface Fnet= the opposing force? Thanks :)
Physics 11
In the absence of air resistance, a ball of mass m is tossed upward to reach a height of 20m. Given that Fg=mg, what is the net force on the ball at the 10m position (half way up)? a)2mg b)mg c)mg/4 d)mg/2 I already got this wrong bc I had no idea how to solve. I have a ...
Physics 11
Ok I will do, thank you :)
Physics 11
Can someone explain what work total is? In my lessons it said Work total is the sum of all work & showed an example of different work being added together. An assignment after that however made me think that may not be the case... Do I need to add the work in some cases or is ...
Physics 11
What I understood was that Wtotal=the sum of all work, but is what I did maybe Wtotal?
Physics 11
A 62kg cyclist changes the speed of a 12kg bicycle from 8.2m/s to 12.7m/s. Determine the work done. I used change in energy = work to find work against inertia which was 3479.85 Then I used V^2=V.^2 + 2ad to get ad=47.025 I then used W=mad to get work against friction, my ...
Physics 11
A girl pushes her little brother on his sled w/ a force of 35N for 840s. How much work does she do if the force of friction I'd 27N? I subtracted the force of friction from the applied force to get my net force of 8N but I don't know where to go from there... Thank you :)
Physics 11
I don't think I have that formula... So mg(mu)d=Ek? making d=190.8 then I can use kinematics to get a & w=mad? :) thanks a ton :)
Physics 11
A 90kg basketball player carries about 720J of kinetic energy when running down the court. If the coefficient of kinetic friction between good runners & the floor is .600, how far does the player skid when trying to stop? Hint: what work was done by friction in bringing the ...
Algerbra
7.f(x)=2x^2-3x+1 13. f(x)=x^2-6x+1=0 *Solve for the zeros/roots of the following quadratic equations by using the quadratic formula* Any help please.....
Physics 11
Ok, I used m1V1 + m2V2=m1V'1 + m2V'2 to get .060kg(0) + 3.1kg(0) = .060kg(580m/s) + (3.1kg)V'2 0=34.8kg-m/s + 3.1kgV'2 -34.8=3.1V'2 -11.23m/s=V'2 Is that right? Thanks again :)
Physics 11
A rifle bullet of mass 60g leaves the muzzle of a rifle with a V=5.8*10^2m/s. If the rifle has a mass of 3.1 kg, with what V will it recoil? I'm at a total loss here because I feel like I don't have enough information... I just need to know what formulas to use with ...
Social studies
A C E
Social studies
Which are functions of money? Store value Producer of resources Unit of account Medium of exchange Record of finances Unit of output
Social studies
1. Which of these people is part of the labor force a.an eighth grader with a paper route b. a retired sales person c. a full time college student d.an auto mechanic•• 2. Which is the best example of frictional unemployment? A plumbers contract with an apartment ...
Social studies
Which is the most likely result of income not rising as quickly as inflation? People are able to buy goods and services The unemployment rate rises as more people look for job•• Many people decide to leave the labor force Consumers buy more goods before inflation ...
Social studies
Which is a likely effect of this change in tax policy? High income people will choose to leave the state•• Non profits will become a large part of the economy•• Consumers in the state will choose to buy fewer things Financial institutions will be less ...
Sociales studies
Wait it's A ... to answer your question public services is service provided by government to people living within its jurisdiction
Sociales studies
D??
Sociales studies
The citizens of a small city have been eager to see more green space in their environment there are several abandoned lots that activists think could be turned into community gardens or parks for people to freely enjoy. 1. For the additional green space to be considered public...
Social studies
2 A is that correct
Social studies
What is one of the things the federales reserve system does? Set income tax rate at the federal level Influence interest rates•• Decided who can open bank account Give loans to bank customers How might the government deal with a huge company that has no competitors ...
Social studies 7
Which job would likely have the lowest income? A job that many people are welling to do•• A job that takes highly specialized skills A job that requires a college diploma A job that requisa lot of travel
Social studies
Thanks for checking my answers
Social studies
Which of these factors contribute to the income potential of a job? a. the education required to be successful at a job•• b. the amount of income a person wants to make at a job c. the special skills needed to do a job well•• d. the enjoyment a person finds...
Physics
A 15kg box is given an initial push so that it slides across the floor & comes to a stop. I the coefficient of friction is .30, a) find Ffr- Fg=mg - Fg=15kg(9.8N/kg)=147N Ffr=mu(Fn) - Ffr=.30(147N)=44.1 b) Find the acceleration of the box. Hint: what is the net force as the ...
Physics
A 15 kg box is given an initial push so that it slides across the floor & comes to a stop. If the coefficient of friction is .30, A) Find the Ffr Fg=mg=Fg=15(9.8)=147N Ffr=mu(Fn)- Ffr=.3*147N=44.1N B)Find the acceleration. Hint: what is the net force as the box slides to a ...
Algebra
a basketball player scored 17 timea during one game. He scored a total of 21 pts,two for each two-pt shot and one for each free throw. How many two-pt shots did he make? How many free throws?
Math
the length of a rectangular window is 6 feet more than its width, w. the area of the window is 100 square feet. which equation could be used to find the dimensions of the window?
6th gr. math
c=s The variable s represents number of additional necklaces and the variable c repres. total # of diamond neck.If louie has 3 neck. in his hand how many are diamond necklaces? please help me solve
Math
Find the exact values for the lengths of the labeled segments a, b and p drawn in green, red, and blue, respectively. Note that r=3 is the radius of the circle, and s=2 is the arc length from the point (3,0) around the circle to the indicated point. (So imagine a triangle ...
Math
For each of the following, fill in the blank to create a perfect-square trinomial: (a) x2 ?6x+ ____ y2 +7y+ __
math
Indicate if there are 0, 1, or 2 triangles with these data. 1) A=30?,b=10,a=12: 2) A=30?,b=10,a=3
Philosophy check my answers
determiine the following passages with the fallacy committed. 1. The world was either created in chaos or by God. There's evidence of order in the world so God must exist. 2. The government has no right to force me to pay the new tax. They have the right to govern over ...
world History
How did the french citizens who witnessed the king louis execution react
world History
How did XVI respond as he faced execution
Math
-3 + n/2 = 9
algebra
A ball is dropped from a height of 30 feet and allowed to bounce until it comes to arrest each time the ball bounces it rebounds to 3/5 of its previous high after which bounce is the boss hi 10.8 feet. I understand the height gets shorter but is there a equation to solving ...
Chemistry
A 0.446-gram sample of iron ore is dissolved in HCl and the iron (Fe solid) is reduced to Fe2+. The solution is then titrated by 38.6mL of 0.105 N KMn)4. Calculate the percentage of Fe in the iron ore sample.