Peoples Physics Concepts

(Marvins-Underground-K-12) #1

http://www.ck12.org Chapter 3. Two-Dimensional and Projectile Motion


3.3 Projectile Motion



  • Explain the parabolic motion of a thrown object.


The aim here is to understand and explain the parabolic motion of a thrown object, known as projectile motion.
Motion in one direction is unrelated to motion in other perpendicular directions. Once the object has been thrown,
the only acceleration is in they(up/down) direction due to gravity. Thex(right/left) direction velocity remains
unchanged.


Guidance


  • In projectile motion, the horizontal displacement of an object from its starting point is called itsrange.

  • Vertical (y) speed is zero only at the highest point of a thrown object’s flight.

  • Since in the absence of air resistance there is no acceleration in the horizontal direction, this component of
    velocity does not change over time. This is a counter-intuitive notion for many. (Air resistance will cause
    velocity to decrease slightly or significantly depending on the object. But this factor is ignored for the time
    being.)

  • Motion in the vertical direction must include the acceleration due to gravity, and therefore the velocity in the
    vertical direction changes over time.

  • The shape of the path of an object undergoing projectile motion in two dimensions is a parabola.


Watch this Explanation


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Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/378
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