Ap Chem help desperately needed?
I know the answers to these, but does anyone know what year these released multiple choice questions are from? I really need to know, because I have to try and find the answers to the rest of it. If you know the answers to the rest of this one, please post them here! Thanks =) Multiple Choice - Refer to the following chemical compounds A) CH4 B) CCl3F C) H2S D) H2O2 E) K2CrO4 1) Commonly used as a disinfectant for minor skin wounds. 2) A refrigerant implicated in the thinning of the stratospheric ozone layer. 3) A major component of the fuel known as natural gas. 4) A yellow solid at room temperature and 1 atm. --------------------- A) CO B) CH4 C) HF D) PH3 E) F2 5) Contains two pi-bonds 6) Has the highest dipole moment 7) Has a molecular geometry that is trigonal pyramidal
Help with Math h.w. needed desperately!?
If anyone can work these out with explanations, it will be greatly appreciated. Thank you. 1. Differentiate sinx= 1+ysiny with respect to x. 2. Show that the tangent to the curves y³-x²y +5y-2x= 6 and x³y²-2y-8x-x⁴=2 at the point (0,1) are perpendicular. 3. Verify that the point p(rcosθ, rsinθ) lies on the circle x²+y²=r². Find dy/dx in terms of θ and hence show that the eq’n of the tangent to the circle at P is xcosθ+ ysinθ= r. If this tangent meets the co-ordinate axes in R and S and if O is the origin, show that 1/OR² + 1/OS²= 1/r². 4. Verify that the point P(acosθ, bsinθ) lies on the ellipse x²/a² +y²/b²=1. Find dy/dx in terms of θ and hence show that the eq’n of the tangent to the ellipse at P is x/a (cosθ) +y/b(sinθ)=1. 5. The eq’n of a curve is 1/x +1/y= 1/a where a is a constant. Prove that dy/dx = -y²/x² and find the eq’n of the tangent to the curve at the point (2a, 2a)
Fallout 3 Help Needed Desperately?
I'm stuck in the Chryslus building. Here's the situation: - The only terminal my guy is able to access is locked out from me because I dgaf'd and pressed whatever. - My lockpick skill is too low to get into the reception area - Making a waypoint to any outer area will lead me to the reception area entrance doors, which, as stated before, I cannot get through due to my low lockpick skill - I'm stuck going back and forth between the basement and lower level offices - I've killed all enemies aside from 2 dogs that are behind a different set of locked doors - My pipboy shows no exits; I only see an entrance to the basement and the reception area (blocked by locked doors) and when I'm inside the basement, again, only reception area entrance (also blocked) and the way up to the lower level offices. - I've been stuck here for 2 hours; I'm in desperate need of help. Please, no one tell me to go to some website for help. I've googled this for an hour, and so far, nothing helps. - I've checked the Fallout wiki. They give no help in exiting the building. PLEASE help me.
Chemistry help needed desperately?
First you need the rxn between decaborane (B10H14) and oxygen. My guess is that you wind up with B2O3 and H2O as products. B10H14+11O2->5B2O3 + 7H2O. So now you have a math problem: 3901 kg= wt B10H14 + wt O2. Call these weights X and Y respectively. Then 11*X/molwt(B10H14) =Y/32. X/molwt(B10H14) is the number of moles of decaborane. The stoichiometry indicates that 11 moles of O2 are needed for each mole of this compound. Y/32 is the number of moles of oxygen. These two equations can be solved simultaneously. 2. You need to first find the volume of copper that is needed to laminate 8900 boards. We have the 3 dimensional values, so this is easily done (easy for me, tough for you). Now we multiply this by 0.825, which represent the volume of copper removed. We multiply that result by 8.96 g/cm^3; HOWEVER, make sure your initial calc is in cm^3. We can convert this weight of copper to g-atoms by dividing by the atomic weight of copper. From the eqtn, for each mole of copper, we need 1 mole of the copper(II)tetraammonium chloride complex reagent. We can then find the mass involved by multiplying moles by its mole wt.
Chemistry Help Needed Desperately!!!!!?
use the equation M1V1 = M2V2 So, (0.60 M) (200.0 mL) = (x) (350.0 mL) [I got 350.0 mL for the final volume by adding the 150mL to 200.0mL] Now just solve for x: x = (0.60 M) (200.0 mL) / (350.0 mL) x = .343 M HNO3 Hope I helped! I assumed you were trying to find the final molarity of HNO3.
Why did you not ask for help when you needed it desperately at your time of struggle? What happened after, and the lessons you learned?
I had no one left to ask.My spouse, my family, my church, many of my friends.... they were all gone.I was alone and scared and my world had been destroyed. I didn't know if I could make it. I was hurting right through me.What happened? People I did not know or barely knew came out of nowhere and became my new family. People I never would have expected to rely on called me, listened to me, bought me groceries, held me while I cried. Good human beings got me through it.I learned that the world is full of amazing people, and that I should never hesitate to be one of those people when someone I know (even peripherally or remotely) needs help. It doesn't have to be a lot or cost a lot of money, just listening to someone or offering a hug might be the thing that gets them through that week. So I make it my goal to always be the one to offer now.
Physics help desperately needed please?
look at the x and y motions separately, and remember the definition of accel: a=(final speed-initial speed)/time in the x direction: ax = 5.1m/s/s = (3845 m/s - v0x)/565 s multiplying through: 5.1m/s/s x 565s = 3845-v0x v0x = 963.5 m/s/s in the y direction, we have: ay = 7.3m/s/s = (5164-vy0)/565s vy0 = 1039.5 m/s so the components of initial velocity are (963.5,1039.5) the mag of the velocity is: sqrt[963.5^2+1039.5^2] = 1417.3m/s the angle of the velocity is given by: tan(theta) = vy/vx = 1039.5/963.5 theta = 47.2 deg
Mechanics Questions. Help Needed Desperately!?
1. Let α be the angle between the inclined plane and the horizontal (tanα = 3/4) The motion is decelerated by the component -mgsinα of the gravity force parallel to the plane, and the friction f = -μN = -μmgsinα, where μ is the friction coefficient and N = mgcosα is the component of gravity force normal to the plan. The acceleration of the motion is A =(f + N)/m = -(sinα + μcosα)g For uniformly decelerated motion, we have the following relation between velocity and displacement v² - v0² = 2A.d d = (v² - v0²) / 2A d = {v² - [2 sqrt(2ga)]²} / -2(sinα + μcosα)g distance at which v = 0 is d = 0 - [2 sqrt(2ga)]² / -2(sinα + μcosα)g d = - (4*2ga) / -2(sinα + μcosα)g d = 8a / 2(sinα + μcosα) d = 4a / (sinα + μcosα) with tanα = 3/4 and μ = 1/4, we get: cos²α = 1 / (1 + tan²α) = 1 / [1 + (3/4)²] = 16 / 25 ==> cosα = 4/5 sin²α = tan²α / (1 + tan²α) = (3/4)² / [1 + (3/4)²] = 9 / 25 ==> sinα = 3/5 d = 4a / [3/5 + (1/4)(4/5)] = 4a / (3/5 + 1/5) d = 4a / (4/5) d = 5a 2. Equation for the displacement: d = v0.t + (1/2)A t² = [v0 + (1/2)At] t For d = 0, t = 0 or t = -2v0 / A The particle come back to O(0) at t = -2v0 / A t = -4sqrt(2ga) / -(sinα + μcosα)g t = 4.sqrt(2a) / (sinα + μcosα).sqrt(g) t = 4.sqrt(2a) / (3/5 + 1/4*4/5).sqrt(g) t = 4.sqrt(2a)/[(4/5)sqrt(g)] t = 5.sqrt(2a/g) (this is different from the given answer by a plus sign, please double check)
If you are away from home in desperate need of help, how do you pick out a stranger and ask for his or her help?
If possible you must go to a gas station, grocery store, shop or business, traffic police, postal mail truck, truck or vehicle with business logo and an address or phone number to atleast have something to rely on or tell about. Just strangers shall be your last resort. Still look for a uniform or someone in work clothes. Ask him if he “work” nearby, and where. An honest person will not hesitate to tell you. That’ll establish his authenticity too(That’s a must if you are in a not-so-safe area). A person in car with license plate number could be asked for help, but don’t jump in for a ride, before asking local shops for help, also if it’s safe to take ride there. If not in desperate hurry, waiting for authentic person for hours is better than made wrong decision in hurry. In any circumstances font tell you’re alone and helpless. Tell him your waiting for someone but he’s late.