If you throw an object
what force/s are on
the object after it leaves your hand?
Only force is gravity (if ignoring air resistance)
Projectiles are any object moving through a
medium (usually the air) that is not supported
by a normal force and without any other
Jumping, free falling, hitting/kicking/throwing a
Are these projectiles
Football being punted?
Cat jumping out of a tree?
A butterfly flying?
Long distance jumping?
A hot air balloon flying?
Space ship launching?
Kinematics in Projectile Motion
Projectiles use the same formulas as before in
We just break them down into motion on the x,
the y, and the resultant.
Rules for Projectiles
Ignoring air resistance
all objects fall with
the same acceleration (gravity)
Horizontal motion does not effect vertical
Vertical is used as the timer (how long it can
stay in the air)
Horizontal motion is constant if no air
resistance is used
If the projectile returns to the same height
the time up = the time down
An elephant and a feather fall in a vacuum
which falls faster?
A bullet is fired and a bullet is dropped from
the same height at the same time
hits the ground first?
A kid kicks a ball at an angle of 30 degrees
what is the acceleration in the horizontal?
Falling from rest
If an object falls from rest
use the kinematic
formulas that ignore initial velocity.
A ball rolling 3.0 m/s across a table that is 1.0 m
off the ground:
How long until it hits the ground? (t = ?)
How far from the table will it hit?
(x = ?)
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