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How are people's finals going? I think most of college's and universities are finished actually. I'm in high school and I got mine tomorrow and Friday.
I need help on some trig questions, please
1. If the point (.57,y) is on the unit circle in Quadrant I, what is the value of y?
2. The needle(the radius) of the scale in the bulk food section of a supermarket is 26 cm long. Find the distance the tip of the needle travels when it rotates 66 degrees.
3.A point on the rim of a wheel has a linear speed of 15 cm/s. If the radius of the wheel is 25 cm, what is the angular speed of the wheels in radians per second?
4. A bicycle wheel has a radius of 13 inches and 4.3 revolutions per second. What is the speed of the bicycle?
5. To find the height of the pole, a surveyor moves 170 feet away from the base of the pole and then, from an eye level of 6 ft, measures the angle of elevation to the top of the pole to be 22 degrees. Find the height of the pole.
For 5, I don't get the eye level of 6 feet part.
Thanks
 
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1) if the point is on the unit circle it means that lenght of origo-(x, y) vector is 1. Hence sqrt(y^2+0.57^2)=1 .
Find y yourself, the quadrant I info is important, it means y will be positive.
4) the length of the surface of the wheel 2*pi*r ===> you go every second 2*pi*r*4.3 inches, that is your speed
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for 5 just draw it out and it should make sense
basically the base of the triangle is 6 feet above the ground
my finals have been hit and miss
got A+ on my japanese and probably 60-70% on my math finals
might be close ;_;
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I finished 2 weeks ago. And I only have exams in the summer.
Here's some little hints, for most of these it helps to draw a diagram.
1. Draw a circle radius 1 centre origin, plot the point, draw a right angled triangle, etc.
2. Use that arc length formula (fraction of 2(pi)(r).
3. Look up v = rw or equivalent
4. After 1 revolution, the bike moves the circumference of the wheel.
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4. Just find the circumference of the circle and multiply it by the revolutions.
pi * 13 * 2 * 4.3, that will give you inches per second.
This stuff is pretty basic, what is this, grade 10 math?
My finals are all done. I think I did quite well on all but one of them. I should be getting my grades soon.
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my god I just finished my junior (HS) year finals today.
I aced my french final
I bombed my physics final. I was hoping for an A and I got like a B- LOL!
I bombed my AP US History final. DBQ was complete bullshit. Even worse than psi storm.
I don't really care about my Literature final. My grade isn't going anywhere
I did pretty good in my calc finals imo.
I don't even fucking know what I did on my international business final. The teacher is just weird.
for #5, I'm pretty sure it just means looking at it from 6 ft above the ground.
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17069 Posts
I played SC instead of studying for physics and math. That's why I got a 70% and a 60% on them.
Ended up with a B+ in physics even though I could've gotten an A, and a B in math even though I could've gotten an A-.
Oh well, whatever.
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im done with mine, gl in yours. D;
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1. If the point (.57,y) is on the unit circle in Quadrant I, what is the value of y?
Pythagorean theorem: y^2 + .57^2 = 1
2. The needle(the radius) of the scale in the bulk food section of a supermarket is 26 cm long. Find the distance the tip of the needle travels when it rotates 66 degrees.
2 * pi * (26) * 66/360 <- 66/360 is the fraction of the entire circumference of the circle
3.A point on the rim of a wheel has a linear speed of 15 cm/s. If the radius of the wheel is 25 cm, what is the angular speed of the wheels in radians per second?
15 / (2 * pi * 25) <- fraction of the entire circle per second
(15 / (2 * pi * 25)) * 2 * pi <- convert to radians
4. A bicycle wheel has a radius of 13 inches and 4.3 revolutions per second. What is the speed of the bicycle?
2 * pi * 13 <- circumference
2 * pi * 13 * 4.3 <- meters per second
5. To find the height of the pole, a surveyor moves 170 feet away from the base of the pole and then, from an eye level of 6 ft, measures the angle of elevation to the top of the pole to be 22 degrees. Find the height of the pole.
For 5, I don't get the eye level of 6 feet part.
O <-eye level
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/\
170 * tan(22) <- height of the pole from eye level
170 * tan(22) + 6 <- height of the pole from the ground
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Ahhh, the days of high school math. I envy thee.
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On December 18 2008 09:35 Empyrean wrote:
I played SC instead of studying for physics and math. That's why I got a 70% and a 60% on them.
Ended up with a B+ in physics even though I could've gotten an A, and a B in math even though I could've gotten an A-.
Oh well, whatever.
+ Show Spoiler +
I think this works here too? All credit to chill.
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I don't have finals for like another month...
If we have no tardies in all our classes then we can get out of 1 exam, mine will be AP Calc even though I'm pretty sure I could ace it, I've been getting like 95-100% on all the quizzes
Organic Chem... so much shit to remember, but I already have a high enough grade that a B-ish won't really effect my A
AP Physics... fuck this shit, I have to take it cuz it's online so my ability to get out of one exam doesn't fly here, I'd definitely get outta this over AP Calc
English 12... pretty easy class, probably won't do toooo well on the exam, english is the bane of my existence, B ish
Comp Programming... pie, will probably be something really simple, it's a very basic class, most people in there couldn't handle simple python so we did VB all semester and MS Logo (I know right is this 1970?)
Consumer Economics... literally the easiest class ever (I wish we had AP econ classes)
Drama... self-explanatory
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EPT![[image loading]](http://www.teamliquid.net/staff/Chill/iccup.png)
