# Search results

1. ### Projectile Motion, package has to land on a moving ship after being droped from plane

Homework Statement A plane flies at 900m and has to deliver a package. It flies at 180 m/s North at 15° below the horizontal. The ships velocity is 40 m/s and it is travelling due north. At what horizontal distance from the ship must the package be dropped for it to land on the ship...
2. ### Deriving the Equation for Period of Simple Pendulum? Is my attempt correct?

Homework Statement I have to derive an equation with the following variables: T= period m= mass Theta= angle l= length and I was told to think of the period as the perimeter of a circle. Homework Equations The Attempt at a Solution C=2\pi r,C/2=\pi r,d=\pi r,(at^2)/2=\pi...
3. ### Pulley but the cable is at an angle?

Homework Statement http://img813.imageshack.us/img813/594/75309500.png [Broken] http://img813.imageshack.us/img813/7166/51848816.png [Broken] I have to find acceleration to calculate how long it takes the heavier box to reach the end of the table. Homework Equations The...
4. ### Rocket fires its engine, force/acceleration

Homework Statement A small space probe of mass 235 kg is traveling at 85.0 m/s. It fires its main engine at an angle of 63.00 to its original direction of travel. The engine produces a thrust of 12,000 N and there is enough fuel on board for a 10.0 s burn. What distance will it have traveled...
5. ### Acceleration from Position vs Time^2 ?

Homework Statement http://img824.imageshack.us/img824/6466/31231242.png [Broken] http://img835.imageshack.us/img835/5220/76022234.png [Broken] It's a free fall problem and I have to calculate a = g Homework Equations g = (2*(d-(vi * t)))/t^2 g = (2d)/t^2 The Attempt at a...
6. ### Quick Question (Epsilon/Delta Limit Proofs)

Homework Statement [PLAIN]http://img641.imageshack.us/img641/2494/mathg.png [Broken] I've worked through it and at the 1st step I get: (1/-e+1)<x<(1/e+1) How do they have (1/e+1)<x<(1/-e+1)? Do you switch the signs of an inequality when you take the inverse of both sides?
7. ### Hyperbolic Sound Travel?

Homework Statement Two recording devices are set 2400 feet apart, with the device at Point A to the west of the device at point B. At a point on a line between the devices, 400 feet from point B, a small amount of explosive is detonated. The recording devices record the time the sound...
8. ### Rotation of Axis and Hyperbolic Sound Travelling Word problem?

Homework Statement 6x^2-6xy+14y^2-45=0 Two recording devices are set 2400 feet apart, with the device at Point A to the west of the device at point B. At a point on a line between the devices, 400 feet from point B, a small amount of explosive is detonated. The recording devices record...
9. ### Hardest Identity Evar involving sum and differences

Homework Statement sin (x) + sin (3x) + sin (5x) + sin (7x) = 4cos(x)cos(2x)sin(4x) Homework Equations sin(a+b)=sin(a)cos(b)+sin(b)cos(a) sin(a-b)=sin(a)cos(b)-sin(b)cos(a) The Attempt at a Solution Me and four of my classmates have tried to do this proof and it kicked our ***...
10. ### Graphing with a ti 84

Homework Statement If I graph an equation with my ti 84, is there anyway I can take the x values in the 2nd [table] spreadsheet of of x and y values and make the x values fractions? They're all decimals and I wan't them in fractions if possible. Can it be done? Homework Equations...

High school stats: 1860 Sat 87-88 GPA Top 33% No extra currics. I got into a nice state school but couldn't afford it (I got 20K but still came short by 10-15K). Now I am at a Community College. I am taking Bio 102/Pre Calc/Engl 101/Speech 101. I want to finish my 2 year Associates in...
12. ### How does one Study ?

How does one "Study"? I'm currently taking: Math 119 (Pre Calc) Engl 101 Spch 101 Bio 102 The Math 119 class is killing me. It's really making me frustrated because I had not expected CC classes to be, you know, hard. For math, I do all the hardest problems in my book, I have access to...
13. ### Impossible Bearing and Triangle word problem.

Homework Statement Radio direction finders are set up at points A and B, 8.68 mi apart on an east-west line. From A it is found that the bearing of a signal from a transmitter is N54.3*E, while from B it is N35.7*W. Find the distance from B, to the nearest hundredth of a mile. A person...
14. ### Quick simple indentity explanation needed

Homework Statement When you have something like and you wanna use the pythagorean's theorem identity but lets say i do it with the 3rd term in the parenthesis, then would this be valid and what about this is this also valid? Homework Equations N/A The Attempt at a...
15. ### Schools Need some guidance as I'm the first of my ancestors to go to college

Need some guidance as I'm the first of my ancestors to go to college :) Well my parents came into the USA in hope of a better future and for a better education, but they could not afford it. Both of my parents are high school dropouts from a 3rd world country, so asking them for guidance is...
16. ### Help needed with Verifying Trigonometric Functions

Homework Statement \frac{secx-cscx}{secx+cscx}=\frac{tanx-1}{tanx+1} \frac{(tan^{2}x - cot^{2}x)}{(tanx + cotx)}= (tanx - cotx) tan^{2}2x+sin^{2}2x+cos^{2}2x=sec^{2}2x cot^{2}2x+cos^{2}2x+sin^{2}2x=csc^{2}2x The Attempt at a Solution I've tried many times in my notebook and i'm...
17. ### Need help with trigonometric problems

Homework Statement http://img135.imageshack.us/img135/4150/trighelp.jpg [Broken] Homework Equations The Attempt at a Solution http://img18.imageshack.us/img18/8480/workz.jpg [Broken] Please help I'm totally confused, if anyone can help I can offer a reward of monetary value :).
18. ### Help needed with trigonometric word problem

Homework Statement http://img135.imageshack.us/img135/4150/trighelp.jpg [Broken] Homework Equations The Attempt at a Solution http://img18.imageshack.us/img18/8480/workz.jpg [Broken] Please help I'm totally confused, if anyone can help I can offer a reward of monetary value :).
19. ### Wierd question involving time and acceleration

Homework Statement A pedestrian is jogging on a path and sees a boat coming towards him. He's moving at 10 km/hr and the boat is moving at 20km/hr, how quickly does the jogger approach the boat? Homework Equations I'm guessing these: Vf = vi + a * t D = vi*t +1/2 a * t^2 Vf^2 =...
20. ### Velocity Time graphs and Displacements

Homework Statement How do i figure out the TOTAL displacement of this graph http://img186.imageshack.us/img186/7677/36947032we7.jpg [Broken] Homework Equations I'm guessing A=1/2bh and A = bh The Attempt at a Solution I've got no idea due to the line crossing the X axis
21. ### Beginnger Coefficient of Kinetic Friction Problem

Homework Statement If you exert 28N of horizontal force while pushing a 10.2 kg box across the surface of a floor at constant velocity, then what is the kinetic friction coefficient between floor and the box? Homework Equations EF = ma Ffk = uK * Fn The Attempt at a Solution...

Please help with Kinematics HAVE MID TERM TOMRROW :(!! I have a mid term tomorrow and I'm in a dire situation. I don't remember how to do kinematics equations like A bus leaves the terminal and travels for 900s at an average velocity of 10 m/s before it stops at its first destination. How...
23. ### Simple Alg 2 Help Needed on Interest

Homework Statement Marianne borrowed 10000. She borrows from a friend at 8%, twice that amount from her bank at 9% and the rest from her Insurance at 5%. She pays a total of 830 in interest for the first year. How much did she borrow from EACH SOURCE?!! Homework Equations ?? The...
24. ### Help with adding vectors with component method (sin/cos/tan)

Homework Statement A ship leaving its port sails due north for 30 miles and then 50 miles in a direction of 60 degrees east of north. At the end of this displacement, where is the ship relative to its port? An army recruit on a training excercise is instructed to walk on a bearing of 6.3...
25. ### Help with Kinematics and Acceleration

Homework Statement A car initially traveling at 15 m/s accelerates at a constant rate of 4.5 m/s^2 over a distance of 45 m. How long does it take the car to cover this distance? Vi: 15 m/s Vf: ___ m/s A: 4.5 m/s^2 Delta D: 45 M Delta T: ___ s Homework Equations I'm guessing I would have to...
26. ### Need ALGEBRA 2 HELP with square roots

Homework Statement simplify m^(9*√5)/m^(√5) The Attempt at a Solution would that equal m^9 or m^(8*√5)
27. ### Forming precipitates

Homework Statement I have H2SO4 + BaCl2 → and need to figure out what it will create. Homework Equations Now I don't know how to figure out ionic charges or the rules of writing ions/chemical equations. I mean tried to break that up in class today into separate ions and my teacher said...
28. ### Determining charges of elements

I know its a rather simple question but if you think about it, it requires much knowledge of d orbital. Is there an easy way a HS student can determine charges of elements using only a periodic table and no prior knowledge of orbitals? My old chem teacher said you could take the element and...
29. ### Ionic equations and Spectator Ions

This is my reaction Pb(NO3)2(aq) + H2SO4(aq) → PbSO4(s) + HNO3(aq) Pb + (NO3)2(aq) + H2 + SO4(aq) → PbSO4(s) + H + NO3(aq) So far I've done that, and now I'm stuck I see h2 and h and NO3 2 molecules and on the left side i see only one NO3 molecule on the right, can I cross out both or do i...
30. ### Ionic equations and Spectator Ions question REALLY SHORT

Homework Statement Pb(NO3)2(aq) + H2SO4(aq) → PbSO3(s) + HNO3(aq) Pb + (NO3)2(aq) + H2 + SO4(aq) → PbSO3(s) + H + NO3(aq) The Attempt at a Solution So far I've done that, and now I'm stuck I see h2 and h can I cross out both or do i have to balance right now? My teacher said you can...