read pp 134 136 do 6 11 12 28 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Read pp. 134-136 Do 6, 11, 12, 28 PowerPoint Presentation
Download Presentation
Read pp. 134-136 Do 6, 11, 12, 28

Loading in 2 Seconds...

play fullscreen
1 / 14

Read pp. 134-136 Do 6, 11, 12, 28 - PowerPoint PPT Presentation


  • 90 Views
  • Uploaded on

Read pp. 134-136 Do 6, 11, 12, 28. Pendula. (or Pendulums, in the vernacular). What is a pendulum? Pendulum: Consists of a massive object called a bob suspended by a string. What is it good for? Keeping time Galileo (what other options did he have?) Clocks

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Read pp. 134-136 Do 6, 11, 12, 28' - onaona


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
pendula

Pendula

(or Pendulums, in the vernacular)

slide3

What is a pendulum?

  • Pendulum: Consists of a massive object called a bob suspended by a string.
  • What is it good for?
  • Keeping time
    • Galileo (what other options did he have?)
    • Clocks
    • Calculating acceleration due to gravity
  • Other, less obvious things
    • Verifying the rotation of the earth
    • Understanding Energy: Potential and Kinetic
    • Study of simple harmonic motion
conservation of energy the pendulum
Conservation of Energy & The Pendulum

Definitions

Potential energy describes the possibility of converting stored energy into motion

Kinetic energy describes the energy of motion

Since (mass)energy can be neither created nor destroyed, potential and kinetic energy can be exchanged interchangeable

This height indicates the distance the pendulum bob “falls” under the influence of gravity. It and gravity determine how much potential there is for motion

We are back at the same height!

And at ½ of a cycle.

Kinetic energy is a measure of how fast the bob is moving.

conservation of energy the pendulum1
Conservation of Energy & The Pendulum

We are back at the same height!

And at ½ of a cycle.

slide7

Kinetic and Potential Energy

Kinetic Energy = ½ m v2

Potential energy = mg D h

slide8

With pendula, we are usually interested in the period

What things might affect the period?

- mass

- angle

- length

- gravity

- wind resistance

What do you think the form of the equation might be?

slide9

Pendulum: Consists of a massive object called a bob suspended by a string

  • Pendula go through periodic motion as follows:

Where:

T = period, or the time to go through one cycle

l = length of pendulum string

g = acceleration of gravity

  • Note:
    • This formula is true for only small angles of θ.
    • What would you expect to find in this equation and is not there?
slide10

The motion of a pendulum is independent of the mass

    • As long as the mass is big enough so that air resistance can be ignored
    • As long as the mass of the string holding the pendulum is very small compared to the mass of the bob

Where:

T = period

l = length of pendulum string

g = acceleration of gravity

slide11

As we increase l, what happens?

As we increase g, what happens?

slide12

As we increase the angle, what happens?

As we increase the mass, what happens?

slide13

Examples:

  • What is the period of a pendulum on Earth with a length of 1m?
  • What is the period of a pendulum on Jupiter with a length of 1m? (ag = 3g)
  • What is the period of a pendulum on the moon with a length of 2m? (ag = 1/6g)
  • What is the length of a pendulum (on Earth) with a period of 10 sec?
  • What is the length of a pendulum (on Earth) with a length of 0.1 sec?
slide14

Examples(2):

  • What would the graph of period vs. length look like?
  • What would the graph of period2 versus length look like?
  • What would the graph of period2 versus g look like?