Homework problem Definition and 419 Threads

  1. S

    How Do You Determine the Minimum Rope Length Between Two Poles?

    two vertical poles PQ and ST are secured by a rope PRS going from the top of the first pole to a Point R on the ground to the top of the second polle. Show that the shortest length of rope occurs when \theta_1=\theta_2 I have found eqn and found the derivative, what do I do to show that it...
  2. J

    Calculating Centre of Mass in Spherical Coordinates | Step-by-Step Guide

    Wondering if someone could help me get this answer. I don't get spherical coordinates at all. The volume of the region given in spherical coordinates by the inequalities 3 less than or equal to rho less than or equal to 5 0 less than or equal to phi less than or equal to pi/6 -pi/6 less...
  3. T

    Friction Force Homework Problem

    Hello, i have been asking a lot of question lately, i had 60 questions to do for hw, and I'm kinda confused on some of them... A 0.5kg block is placed on top of a 1.0kg block, the coefficient of static friction between the two blocks is 0.35. The cofficient of kinetic friction between the...
  4. M

    Why Does Friction Allow Different Car Accelerations on Ice and Road?

    I was wondering about these questions. Please guide me. 1) We cannot drive a car on ice because there is no force on the car which acts horizontally. It means that when we press the accelertor, we provide only the rotational motion to the wheels. Now, when we drive on a road, friction provides...
  5. A

    Does Point A Have Maximum or Minimum Intensity?

    Hi guys, Couldn't figure this question out even after some thinking through. Hope someone can help me here. 2 loudspeakers are placed 1.2m vetrically apart. The point A is the horizontal distance of 1.6m from the top speaker. Both speakers are operating in phase with a steady freq of 400Hz...
  6. V

    Help Needed: Solving A.P. Physics Homework Problem

    This question, from a previous A.P physics exam, was given as a homework problem. I am wondering if anybody could tell me if I am on the right track or totally wrong. Three blocks of masses 1.0, 2.0, and 4.0 kilograms are connected by mass less strings, one of which passes over a...
  7. P

    Proving Momentum Conservation: A Physics Homework Problem

    so here i am doing my physics homework. everythings fine, but then i get this whopper of a problem, which is for major marks, and i can't seem to solve it for some reason. here she is: a ramp is setup on the edge of a table a ball slides down this ramp and picks up speed. just as...
  8. N

    How Do You Solve This Elliptical Integral with a Coordinate Transformation?

    2c\int_{x=-a}^a\int_{y=-b\sqrt{1-\frac{x^2}{a^2}}}^{b\sqrt{1-\frac{x^2}{a^2}}}\sqrt{1-\frac{x^2}{a^2}-\frac{y^2}{b^2}}dydx Can you help me with this integral?
  9. C

    How Do You Calculate the Change in Momentum of a Billiard Ball?

    I have this problem that I'm not sure I am on the right track. The problem is A .20 kg billiard ball traveling at a speed of 15m/s strikes the side rail of the pool table at an angle of 60 degrees. If the ball rebounds at the same speed and angle, what is the cahnge in its momentum. I have the...
  10. P

    What is the Power Output of a Bird's Song?

    Hello. I was hoping someone could give me a direction to go with this homework problem. I'm having trouble trying to figure it out. Here's the question: Two people relaxing outdoors listen to a bird sing. One person, only 1.00m from the bird, hears the sound with an intesity of 2.80x10^-6...
  11. T

    Superimposed Simple Harmonic Motions: Resultant Time Period Analysis

    what is the resultant time period when two simple harmonic motions of time periods 3s and 4s superimpose
  12. P

    How Does Projectile Motion Affect a Coconut's Flight from a Tree?

    A monkey throws a 25kg coconut from the top of a 15m high redwood with an initial velocity of 10 m/sec at an angle of 30 degrees. Find the following: A)Maximum height relative to the foot of the tree B)TIme for the entire journey C) Distance from the foot of the tree where it lands D)KE at the...
  13. P

    Need help with homework problem - Archimede's principle

    Hello all. I am new to this site and was hoping someone could help me with a homework problem I'm trying to do. Here's the problem: A small ferryboat is 4.0m wide, 6.0m long. When a loaded truck pulls onto it, the boat sinks an additional 4.0cm into the river. What is the weight of the...
  14. M

    Help Me Solve a Physics Homework Problem - Lagrange Points

    Hey a friend asked me for help on his physics homework, and I found this place and was wondering if you guys could help me out. 2: In 1772, the famed Italian-French mathematician Joseph Louis Lagrange was working on the infamous three-body problem when he discovered an intersting quirk in the...
  15. C

    What Is the Trajectory of an Object Dropped from an Airplane?

    Suppose you drop an object from an airplane traveling at a constant velocity, and further suppose that air resistance doesn't affect the falling object. What will be its falling path as observed by someone at rest on the ground, not directly below but off to the side where a clear view can be...
  16. T

    How Do You Calculate the Speed of a Ball Returning to the Bottom of an Incline?

    when a ball is rolled up an incline plane,the incline degree,the distance that it goes are given.the time that it require to reach the highest point is also given.but,how to find the speed when it gets back to the bottom?? pls help thanx
  17. S

    Solve DE: dy/dt = 2*(abs(sqrt(y)))

    Consider dy/dt = 2*(abs(sqrt(y))) 1.Show that y(t)=0 is a solution for all t. I did this part 2.Find all solutions (hint, give solution like y(t)=... for t>=0, y(t)=... t<0). He told us in class that t=0 isn't necessarily the point we should be concerned with 3.Why doesn't this...
  18. B

    How Does an Electromagnetic Bell Work?

    I am stuck on this homework question and would apprieciate a bit of help please. Put the following sentences in the correct order to explain how the bell works. *The springy metal pulls back the hammer *A current flows through the electromagnet *At the same time, the circuit is...
  19. M

    Calculating Volume of Earth Using Radius 6.37x10^6m and Correct Sig Figs

    The radius of the Earth is 6.37X10^6 meters. Determine the volume of the Earth to the correct number of sig figures. to find the volume I used 4/3 (3.14)(6.37x10^6)^3 3.14(2.58x10^20) = 8.10x10^20 4/3 or...
  20. P

    Taylor series homework problem

    Dear friends, I have a question on a taylor series, that is this one: A·e^(i (x)) That is: cos (x)+ i sin (x) becouse of the taylor's. But, is this wrong? A·e^(v (x)) = cos (x)+ v sin (x) (v is a vector). Tks.
  21. M

    Quick Question so I can finish this homework problem.

    I'm doing a physical pendulum problem involving a rigid rod of .720m in length attached to a string of 1.00 meters in length. I'm supposed to find its period. I can do the problem but I'm having trouble calculating the rods moment of inertia. Parrallel Axis Theorem: I = Icm + MD^2 Icm =...
  22. G

    Struggling with a Homework Problem - Need Assistance

    I received a homework problem that I need guidance on where to start. What is the longest vertical soda straw you could possibly drink from? I do not know where to start on this problem. A small push in the right direction would be greatly appreciated.
  23. G

    =Homework Problem: Longest Vertical Soda Straw

    I received a homework problem that I need guidance on where to start. What is the longest vertical soda straw you could possibly drink from? I do not know where to start on this problem. A small push in the right direction would be greatly appreciated.
  24. D

    How Do You Calculate the Force of a Falling Book on the Floor?

    a book falls off a bookshelf and hits the floor. given this info calculate the force of the book on the floor. mass of the book 1.5kg the book touched the floor for .3 sec. the velocity of the book the moment the book hit the floor 3m/s. the velocity of the book when it bounced off the floor...
  25. N

    How to Calculate Force of Water in Rotating Pail | Physics Problem

    a pail of water is rotated in a vertical circle of r=1.4m acceleration of gravity 9.8m/s^2 the pail is rotated at a constant rate so it has the minimum speed at all points along its circular path. the water has a mass m. when the pail is at the bottom of the circle, what is the magnitude of...
  26. A

    Calculating Time on the Moon for a Pendulum Clock

    A certain pendulum clock that works perfectly on Earth is taken to the moon, where g=1.63m/s^2. The clock is started at 12:00:00AM and runs for one Earth day (24 hours). What will be the reading for the hours? Answer in units of h. I'm stumped. I know that the period for the pendulum on...
  27. L

    Solve Tricky Homework Problem: Ice Flake Speed in Hemispherical Bowl

    In this problem, a 1.90 g ice flake is released from the edge of a hemispherical bowl whose radius r is 15.0 cm. The flake-bowl contact is frictionless. a) What is the speed of the flake when it reaches the bottom of the bowl? (b) If we substituted a second flake with twice the mass, what...
  28. H

    How Is Work Calculated When Lifting and Carrying a Cement Block?

    A person lifts a 5.5 kg cement block a vertical distance 1.2 m and then carries the block horizontally a distance 7.3 m. Determine the work done by the person and by the force of gravity in this process. How much work is done by the person and the force of gravity? Would you break this up...
  29. T

    Simplify homework problem help

    hello i have to simplify this : sin(a)sin(b-c) + sin(b)sin(c-a) + sin(c)sin(a-b) I did simplify it and I got it equal to zero. But my problem is, I did too many steps in order to do that. Does anyone have a shorter way to simplify that ?? thx!
  30. J

    What is the acceleration of the masses in this physics homework problem?

    I think someone may have previously asked for help on a problem similar to this one: There are three blocks connected by a string. m1 is 0.5kg, m2 is 1.7kg. m1, and m2 are connected at the top of a surface and m3=2.9kg, is hanging of the end of a pulley. looks kinda like this: [ m1 ]----[...
  31. G

    Is This the Correct Way to Graph the Domain of a Function in Calc 3?

    Hello guys I am not sure if I am doing this right. If you could offer any advice or point out my mistakes I would appreciate it. Problem: Sketch the graph of the domain of f(x,y,z) = \frac{1}{x^2+y^2-z} Domain: (x,y,z) \in R^3 \mid x^2+y^2 does not equal z Graph: I set f(x,y,z) = 1 and...
  32. B

    Contact forces homework problem

    Hello, I have a problem and I would like to check my answers: A mass m1 rests on top of another mass m2 , which in turn rests on a frictionless horizontal surface. A light cord is attached to m2 ,which is used to pull on it witha force F. a) Find the acceleration ofeach object when...
  33. 2

    Linearly polarized light homework problem

    You need to rotate the polarization direction of some linearly polarized light by an angle φ. That is, the light is initially linearly polarized along some direction (let's call it the y direction), and you need to change it so that the polarization direction is φ away from the y direction. In...
  34. S

    Proton Vertical Displacement in Electric Field

    A proton has an initial velocity of 9.4x10^6 m/s in the horizontal direction. It enters a uniform electric field of 28800 N/C directed vertically. What is the vertical displacement of the proton after the electric field acts on it for 7.1202 ns, the time it takes the proton to travel 0.067 m...
  35. P

    What is the speed of a train based on observed changes in frequency?

    I have been working on this problem for over a half hour. I'm not sure where I'm going wrong with it. If anyone could help me out I would really appreciate it. You stand by the railroad tracks as a train passes by. You hear a 1000 Hz frequency when the train approaches, which changes to...
  36. S

    How can you use a substitution to solve a quartic equation?

    Solve for x: x^2+x^2/(x+1)^2=3 I got the final equation but I am unable to get the it form there. x^4-x^2+2x^3-6x-3=0
  37. H

    What is the mistake in finding the volume using spherical coordinates?

    I'm having a problem seeing where I went wrong with this question... S is the solid bounded above by the sphere x^2 + y^2 + z^2 = 8 and below by the paraboloid x^2 + y^2 = 2z. Solve this using spherical coordinates The correct answer is \displaystyle{\frac{4\Pi}{3}}(8\sqrt{2}-7) Here...
  38. B

    Infinitely Many Solutions? A Homework Problem to Investigate

    I had a homework problem and i was wondering if anyone could help me out with it. It is a true or fasle question that requires explanation whether true or false. It goes like this...If A is a singular n by n matrix, then A*x=b has infinitely many solutions.(True or False)
  39. M

    How Do You Calculate the Final Concentration of a Mixed HCl Solution?

    200 ml of a 6 M HCl solution is added to 400ml of a 1.50 M HCl solution. find the concentration of the mixture. here is what I think should be done: (6M)(V concentration)=(.8L)(1.50M) can i add the two volumes together? Is this correct?
  40. A

    Angular momentum Homework Problem

    This is a problem I'm having a world of problem with: A. What is the angular momentum of a 2.56 kg uniform cylindrical grinding wheel of radius 17.5 cm when rotating at 1480 rpm? Correct: 6.08 kg*m^2/s B. How much torque is required to stop it in 6.50 s? So after 5 tries, I get that...
  41. D

    Help Me Solve a Homework Problem Regarding Planet X's Satellites

    i was hoping somebody could give me a hand with a homework problem i have . first here's the question . -> Planet X has two satellites . A and B . Both orbits are circular . Satellite A's orbital radius is 4 times B's orbital radius . calculate the following ratios . a) A's orbital...
  42. S

    Calculating Capacitor Charge and Potential Difference in Series

    A capacitor C1 carries a charge Q0. Is is then connected directly to a second, uncharged, capacitor C2. What charge will each carry now? Q1 = Q0C1/(C1 + C2); Q2 = Q0C2/(C1 + C2) What will be the potential difference across each? V = Q0 / (C1 + C2) -------||-------||--------...
  43. S

    Calculating Diver Velocity and Maximum Height in a 3.0m Board Dive

    A diver springs upward with an initial speed of 1.7 m/s from a 3.0 m board. a. Find the velocity with which he strikes the water. (Hint: When the diver reaches the water, his displacement is y = -3.0 m (measured from the board), assuming that the downward direction is chosen as the negative...
  44. P

    Can A or B be finite if A cross B is not the empty set?

    sets A and B. A cross B not equals the empty set. Prove that A or B is finite. I think that you can't... don't ask me for my work because I have none.
  45. S

    How Fast Does Someone Travel Standing on the Equator?

    As the Earth rotates through one revolution, a person standing on the equator traces out a circular path whose radius is equal to the radius of the Earth (6.38*10^6). What is the average speed of this person in meters per second and miles per hour? I am really having trouble figuring out...
  46. C

    How is the Approximation of \( e^r \) Derived in Discrete Compounding?

    Hello all For discrete compunding, we have after n years (1+r)^n where r is the interest rate. IF we receive m interest payments at a rate of \frac {r}{m} then our discrete compounding equation becomes (1+ \frac{r}{m})^m = e^{m\log(1+(\frac{r}{m}))} \doteq e^r After time t we will have...
  47. N

    Homework problem Leaking faucet

    Homework problem "Leaking faucet" Problem : Leonardo da Vinci constructed an apparatus consisting of two vertical boards hinged together on one side and covered with blotting paper on the inside faces. A leaking water tap let's drops fall down between the boards at presumable equal intervals...
  48. P

    Free body diagram Homework Problem

    Can someone please help with this problem. I'm lost! 1. A 150 kg bear walks out onto a beam as illustrated in Fig P8.20 trying to get to a picnic basket with mass 10kg. The beam is 6m long and has mass 40kg (you can consider its weight to be concentrated at a point 3m from the wall. (a)...
  49. A

    Spring Mechanics homework problem

    There are N weights, each of mass M, connected as shown. At the moment of cutting the top spring, what will be the acceleration of the top and bottom weights? Thanks ahead :biggrin:
  50. D

    Are My Partial Derivatives Correct for Linearization?

    Original question: Let f(x,y) = ln(xy) + yzcos(xz). Find the linearization of f at the point (1,1,pi/2). Use this linearization to estimate the change in the value of the function resulting from moving from (1, 1, pi/2) to (1.1, 1.2, pi/2 + 0.2). I believe the first steps to completing...
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