10/7/10

Post date: Oct 07, 2010 1:19:9 PM

• • Questions on page 130: 25, 29, 37?

  • Quiz 8 - adding vectors, objects in equilibrium, objects on an inclined plane

  • Intro to projectile motion

    • Has a horizontal and vertical component

    • Projectile - an object moving through space horizontally and vertically with gravity being the only force acting on it

    • Vertical motion and horizontal motion don't affect each other (a falling bullet hits the ground at the same time as a bullet shot horizontally)

    • Can use all the chapter 4 equations, but now in X or Y directions

    • Given information:

• • • Equations:

      • Vfx = Vix + (ax)(t), Vfy = Viy + (ay)(t)

      • dx = 1/2 (Vix + Vfx)(t), dy = 1/2 (Viy + Vfy)(t)

      • dx = (Vix)(t) + 1/2(ax)(t^2), dy = (Viy)(t) + 1/2(ay)(t^2)

      • (Vfx)^2 = (Vix)^2 + 2(ax)(dx), (Vfy)^2 = (Viy)^2 + 2(ay)(dy)

    • t is the same for both x and y

    • acceleration in the x direction is zero (no horizontal forces), acceleration in y direction is -9.80 m/s/s .

    • vi and vf in the x direction will be the same (horizontal velocity is constant)

• • Projectile Lab

    • Goal: find the angle that gives the largest range (dx) for a ping pong projectile, determine the relationship between range and angle, collect enough data to accurately hit a target with the projectile

    • Procedure: Launch ping pong balls at various angles (multiple times for each angle) to determine the relationship, try numerous trials in area of greatest range to determine a precise angle for the maximum range.

  • This is a full lab write-up, due Monday, 10/18