Objects Moving In TWO dimensions Horizontal and Vertical
Projectiles must have displacement, and velocity and acceleration
Each has horizontal (x) and vertical (y) components
Slide 3
Projectiles will have constant vertical acceleration 9.81m/s 2
on Earth Projectiles will have constant horizontal velocity The
horizontal displacement (d x ) is called the range
Slide 4
For projectiles, the equations are used twice Horizontal
components of motion vertical components of motion
Slide 5
Objects fired Horizontally Initial horizontal velocity is
LOCKED at a single value Initial horizontal velocity is LOCKED at a
single value Initial vertical velocity is ZERO Initial vertical
velocity is ZERO Horizontal Acceleration is ZERO Horizontal
Acceleration is ZERO Vertical Acceleration is g Vertical
Acceleration is g Displacements, times, and velocities can be
determined using equations for motion Displacements, times, and
velocities can be determined using equations for motion
Slide 6
Horizontal projectiles will accelerate downward at the same
rate as something that is dropped from the same height Therefore
they hit the ground at the same time!
Slide 7
A furry bunny rabbit is dropped out of a plane flying
horizontally at an altitude of 490 m with a velocity of 250 m/s.
The bunny rabbit falls freely to a concrete patio on the ground.
Calculate the time required for the bunny rabbit to hit the ground.
Calculate the horizontal distance covered by the bunny rabbit from
drop point to impact point.
Slide 8
Slide 9
A Chinchilla is released from a plane from 100 m above the
ground. The plane was flying along at 22.5 m/s East. How far from
the release point above the ground will the ugly rodent land?
Slide 10
Slide 11
A squirrel is thrown horizontally at 15m/s from the top of a
cliff that is 44 m high. How long does it take for the squirrel to
hit the ground How far from the base of the cliff does the squirrel
hit the ground? How fast is it falling vertically the instant
before it explodes all over the ground?
Slide 12
Slide 13
A prairie dog is being chased by a deranged physicist. It runs
away and jumps over the edge of a canyon because it is
unintelligent. The rodent was running with a velocity of 10 m/s and
it fell 200m to the valley floor. How long does it take for the
ugly prairie dog to hit the ground How far from the base of the
cliff does the rodent hit the ground? What was the rodents
horizontal velocity the instant before it explodes all over the
ground?
Slide 14
Objects fired at Angles Initial horizontal velocity is LOCKED
at a single value Initial horizontal velocity is LOCKED at a single
value v ix and v iy are found with TRIG v ix and v iy are found
with TRIG a x = ZERO a y = -9.81m/s 2 a x = ZERO a y = -9.81m/s 2
Vertical Acceleration is g Vertical Acceleration is g Max Height
Vertical Velocity = ZERO (also flight time) Max Height Vertical
Velocity = ZERO (also flight time)
Slide 15
Draw diagrams of the situations! 45 degrees gives the HIGHEST
RANGE!
Slide 16
To solve for any variable determine if it is horizontal or
vertical Use only the horizontal OR only vertical components in an
equation Objects launched at 45 will have a maximum horizontal
distance (range)
Slide 17
A Vole is launched with a slingshot at an angle of 40 degrees.
A radar gun clocks the flying rodent at 50 m/s. What is the rodents
horizontal velocity? What is the rodents horizontal velocity? What
is the rodents vertical velocity? What is the rodents vertical
velocity? What is the rodents total flight time? What is the
rodents total flight time?
Slide 18
Slide 19
Slide 20
A guinea pig is strapped to a missile and fired with an initial
velocity of 300 m/s at an angle of 30.0 above the ground. After a
flight time of 30.6 seconds the guinea pig returns to level ground
and explodes. Calculate the initial horizontal and vertical
components of the velocity Calculate the maximum height of the
guinea pig above the ground Calculate how far from the launch site
the guinea pig explodes
Slide 21
A chipmunk was launched from a crossbow with an initial
velocity of 44.7 m/s at an angle of 66 degrees above the horizontal
a) What was the maximum height reached by the rodent? b) How long
did the chipmunk take to return to the launching height (0m) c) How
far from the launch position did the chipmunk land and
combust?
Slide 22
Your teacher kicks a woodchuck from ground level with an
initial velocity of 27 m/s at 30 degrees above the horizontal. a)
Find the hang time of the rodent b) Find the range (how far away it
landed) c) What was the maximum height reached by the
woodchuck?