Objectiveto Understand the Behaviour of Projectiles in Earth S Gravitational Field

SPH 4UProjectile Motion Study

Objectiveto understand the behaviour of projectiles in Earth’s gravitational field

Procedure

1. Find a suitable projectile that can be easily picked up by video. Use the Vernier Video Physics app on the iPad.

1. Capture video* of these projectile motions as the projectile falls to the ground:

a)Vertical drop from the top of a flat table

b)Rolled with an initial constant forward velocity (left to right) from the same flat table

c)Thrown at a small projectile angle (left to right)

d)Thrown at a larger projectile angle (left to right)

* Make sure that the path of the projectile is parallel to the face of the iPad.

1. Mark the frames of each motion using the app from release until impact.

1. Move the origin to be on the bottom left, or on the first marked dot.

1. For each captured video there will be three (+2) graphs. Sketch, or print, all five graphs for each of the projectile motions from above. THINK: how can I conserve paper?

1. Beside each graph, comment on the motion of the projectile in the context of the graph. Include terms such as: velocity, acceleration, displacement, constant.

Discussion

1. What is true about the shape of the height vs. distance graphs for each motion?

1. Describe the motion in the x-direction for cases b) to d). Reference properties of the graphs to support your description.

1. Describe the motion in the y-direction for cases a) to d). Reference properties of the graphs to support your description. What is happening to the projectile when the y-velocity graph crosses the time axis?

1. Compare the times for the projectile to hit the ground in cases a) and b).

1. Study case c). What do you notice about the vertical speed of the projectile at the beginning of the flight, and the vertical speed at the same height but on the way down? Repeat for case d).

1. Go to PhET (http://phet.colorado.edu/en/simulation/projectile-motion). RunProjectile MotionDetermine the effects of changing a projectile’s:
2. Launch angle (use constant mass and initial velocity and change launch angles: 25°, 30°, 45°, 60° and 65°).
3. Mass (use constant speed, and constant angle)
4. Initial speed (use constant mass, and constant angle)

Group Members:

Criteria

• demonstrates an understanding of projectile motion

• evidence and reasoning supports this understanding

• thorough demonstration with strong reasoning and evidence

• effective demonstration with good reasons & evidence

• some demonstration with reasoning and evidence

• get off the stage; you haven’t demonstrated anything of real value

• PhET simulation
• addresses variables
• considers complementary launch angles; and max. range
• provides evidence

• thorough / insightful responses
• support from simulations clearly demonstrates effects of each variable
• clearly connects launch angles and range

• considerably useful responses
• support from simulations demonstrates effects of each variable

• connects launch angles and range with good evidence

• some insightful responses
• support from simulations somewhat demonstrates effects of each variable
• connects launch angles and range to some degree

• doesn’t really get it; there is limited to no relation between flight and each variable

• the evidence sucks

Comments:

\sph4U\kinematics\proj motion study s14.doc