Projectile Motion

Characteristics of Vertical motion of a projectile

1. Force = Weight (the pull of gravity acting on the object) 2. Acceleration = -9.8 m/s/s 3. Velocity changes 9.8 m/s per second

Characteristics of horizontal motion of a projectile

1. Force = none 2. Acceleration = none 3. Velocity is constant due to inertia

What are some examples of projectiles?

1. an object dropped from rest 2. an object thrown vertically upwards 3. an object thrown upward at an angle

A stunt person jumped from the roof of one building to the balcony of another building 5 meters below. The distance between the 2 buildings is 3 meters. What is the minimum horizontal velocity the stunt person must have to accomplish this jump ( ignore air resistance)

Answer 2.96 m/s Solution ∆y = -5m ∆x = 3m) ay = g=9.8m/s² ∆y = 1/2 ay(∆t)² So that ∆t = square root of 2∆y/-g velocity avg = ∆x/∆t = below equation = ∆x (square root -g/2∆y) = (3.0m) (square root (-9.8)/2(-5) = 2.96 m/s

Projectile

Any object that moves through the air or through space under the influence of gravity.

How can a projectile have horizontal displacement even though its vertical displacement is zero?

If the object is launched and caught from the same initial vertical position, vertical displacement will be zero. ( because it was moving 1st up then down the same distance while moving horizontally

Trajectory

The curved path that an object makes in space, or that a thrown object follows as it rises and falls to earth.

Range

The horizontal distance traveled by a projectile.

The motion of a projectile in free fall is characterized by:

Vx = constant and ay = -g

Parabolic

curved path taken by a projectile.

For an object to be a projectile it must be in free fall with an initial velocity that is _________________

have a horizontal component

In the absence of air resistance, the path of a projectile is what shape?

parabolic

Assuming no air friction and ay = -g, the horizontal displacement of a projectile depends on what

vertical component and the horizontal component of its initial velocity