Calculus

posted by .

A flower pot is dropped from a point 12 feet above the ground,so that it will land 4 feet from the base of a 12 foot lamppost. At what rate is the shodow of the flower pot moving along the ground when the pot is 8 feet above the ground?

  • Calculus -

    height y = 12 - 16t^2
    shadow at x, similar triangles, so
    x/12 = (x-4)/y
    or,
    xy = 12x - 48

    y dx/dt + x dy/dt = 12 dx/dt
    y=8 when t=1/2
    x=6 when y=8

    (12 - 16t^2) dx/dt + x (-32t) = 12 dx/dt
    at t=1/2,
    8 dx/dt - 96 = 12 dx/dt
    dx/dt = 96/-4 = -24 ft/s

  • Calculus - PS -

    Oops.
    x=12 when y=8

    make the change and percolate it through the rest of the solution.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    As you look out of your dorm window, a flower pot suddenly falls past. The pot is visible for a time t, and the vertical length of your window is L_w. Take down to be the positive direction, so that downward velocities are positive …
  2. Physics

    A drowsy cat spots a flower pot that sails first up and then down past an open window. The pot is in view for a total of 0.50s. And the top to bottom height of the window is 2.00m. How high above the window top does the flower pot …
  3. physics gr 12

    A flower pot is dropped from the balconey of an apartment 28.5 metres above the ground. At a time of 1 second after the pot is dropped a ball is thrown vertically downwards from the balconey one story below 26 metres above the ground. …
  4. Physics

    The Flower Pot: A flower pot falls off a windowsill and falls past the window below. It takes .3 s to travel from the top of the window to the bottom of the window which is 2.2 m tall. From what height above the top of the window did …
  5. Physics

    A man holds a flower pot out a window 12m from the ground. He tosses the pot upward with a speed of 5m/s. How long does it take the pot to reach the ground?
  6. physic

    As you look out of your dorm window, a flower pot suddenly falls past. The pot is visible for a time t, and the vertical length of your window is Lw. Take down to be the positive direction, so that downward velocities are positive …
  7. General Physics

    A 6 kg flower pot falls from a window ledge 10 meters above the ground. a) What is the Kinetic Energy of the flower pot just as it reaches the ground?
  8. physic

    As you look out of your dorm window, a flower pot suddenly falls past. The pot is visible for a time t, and the vertical length of your window is Lw. Take down to be the positive direction, so that downward velocities are positive …
  9. Physics

    3.A brown flower pot is dropped from an open window from the top floor of a brick apartment building on a Sunday afternoon in April. It fell 3.00 seconds before crashing into multiple pieces on the wet sidewalk below. How far did the …
  10. Physics

    3.A brown flower pot is dropped from an open window from the top floor of a brick apartment building on a Sunday afternoon in April. It fell 3.00 seconds before crashing into multiple pieces on the wet sidewalk below. How far did the …

More Similar Questions