Recent content by quick

  1. Q

    Normalize Function: F(theta)=2*e(-theta)*sin(2*theta)

    i need to normalize(F/Fmax) the function: F(theta)=2*e(-theta)*sin(2*theta) where theta is <= pi/2 and F(theta) is 0 otherwise. theta can basically go to negative infinity which would make Fmax very large.
  2. Q

    Admittance parameters and input impedance

    http://img420.imageshack.us/img420/9300/img02643tt.jpg hello this is the problem i am working on. i started out by using the admittance parameter equation i1 = y11*v1 + y12*v2 i2 = y21*v1 + y22*v2 so i1 is 20/50 by ohms law. so i1 = 0.4 so by the first equation i get v2 = 32 V. also...
  3. Q

    Transfer Functions: Vo = Vi Calculation Help

    http://img66.imageshack.us/img66/9784/prob17zo.jpg j*omega = s so for a, i got Vo = Vi * (sL/(sL+R+1/sc)) so H(s) = sL/(sL+R+1/sc) and i multiplied it by s/s to get rid of s in in denominator of the 1/sc term to get s^2*L/(s^2*L+Rs+1/c) is this correct? for the second one i got...
  4. Q

    Potential of point charges

    Two positive point charges q are located on the y-axis at +-(1/2)s. Find an expression for the potential along the x-axis. Express your answer in terms of epsilon_0, pi, q, x, and s. for this one, i know V = (1/4*pi*epsilon_0)*q/r. so i was thinking its just like finding the potential of...
  5. Q

    How Long Does It Take for a 3 Gram Mass to Reach Maximum Height with Resistance?

    a 3 gram mass is projected vertically upward from the Earth's surface at an initial velocity of 1000 cm/sec and moves through a medium that offers a resisting force of 3 |v|. how long does it take to reach its maximum height? assume w = mg, where g = 9.80. i started by using m*(dv/dt) =...
  6. Q

    Calculating the Minimum Height for a Steel "Boat" to Float

    The bottom of a steel "boat" is a 6.00 m x 9.00 m x 5.00 cm piece of steel(density of steel = 7900 kg/m^3) . The sides are made of 0.460 cm-thick steel. what minimum height must the sides have for this boat to float in perfectly calm water? in cm i have that F_B (buoyancy force) is equal...
  7. Q

    Angular momentum of a merry-go-round

    ok for the first question, i have the initial angular momentum as (1/2)(m_disk)(radius)^2*(omega_i) + m_john*radius^2*(omega_john){which using v = r*omega, i get v/r}/ (1/2)*m_disk*radius^2 + m_john*radius^2. after doing that, i still get the wrong answer. should the disk spin faster after john...
  8. Q

    Angular momentum of a merry-go-round

    1) A merry-go-round is a common piece of playground equipment. A 3.0-m-diameter merry-go-round with a mass of 250 kg is spinning at 20 rpm. John runs tangent to the merry-go-round at 5.0 m/s, in the same direction that it is turning, and jumps onto the outer edge. John's mass is 30 kg. What is...
  9. Q

    Solving for Tension in Masses Connected by String Over Pulley

    Blocks of mass m_1 and m_2 are connected by a massless string that passes over the frictionless pulley in the figure. Mass m_1 slides on a horizontal frictionless surface. Mass m_2 is released while the blocks are at rest. http://s93755476.onlinehome.us/stuff/knight.Figure.13.68.jpg i...
  10. Q

    Find Moment of Inertia of Figure w/ M, L, m_1 & m_2

    i need to find the moment of inertia of this figure http://s93755476.onlinehome.us/stuff/knight.Figure.13.54.jpg and express my answer in terms of M, L, m_1, and m_2. i tried using the parallel axis theorem using (1/12)ML^2 since it is a thin rod with the axis of rotation about the center...
  11. Q

    Work transfer and energy conservation

    1)A gardener pushes a 12 kg lawnmower whose handle is tilted up 37 degrees above horizontal. The lawnmower's coefficient of rolling friction is 0.15. How much power does the gardener have to supply to push the lawnmower at a constant speed of 1.2 m/s? not really sure where to begin with this...
  12. Q

    Energy, Work and circular motion

    ok this first one is rated as a fairly tough problem. 1) A pendulum is formed from a small ball of mass m on a string of length L. As the figure shows, a peg is height h = L/3 above the pendulum's lowest point. From what minimum angle theta must the pendulum be released in order for the ball...
  13. Q

    Momentum Conservation in Tennis Ball Collision

    ok i got a little farther... basically i set it up like m_r*v_r + m_b*v_b = m_r2*v_r2' + m_b2*v_b2'. where m_r is the mass of racket v_r is velocity of racket m_b is mass of ball and v_b is velocity of ball and same for other side except they are the final values. i am given all of the values...
  14. Q

    Momentum Conservation in Tennis Ball Collision

    A tennis player swings her 1000 g racket with a speed of 8.00 m/s. She hits a 60 g tennis ball that was approaching her at a speed of 11.0 m/s. The ball rebounds at 36.0 m/s. 1)How fast is her racket moving immediately after the impact? You can ignore the interaction of the racket with her...
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