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A soccer player kicks a soccer twice with the same force and contact time. One kick was at an angle of 20 degrees and the other kick was at an angle of 40 degrees. Which soccer ball went further? (greater dx)

How many things would you have
to get right to make this work?

Amazing_Jump

By the way, this is a fake

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Fill in the Blank Notes

2. Projectile fired at an angle
(not 0 or 90)

Projectile Path is Parabolic

Baseball Throw
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Victoria Lollo - Class of 2007

Angle and Intitial Velocities

- Projectile fired at 5 m/s:

if Ө = 0

V_ix = 5 m/s, V_iy = 0

if Ө = 90

then .....

V_ix= 0 m/s and V_iy = 5 m/s

If angle is not 0 or 90 the
initial velocity is
part vertical and part horizontal

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*** To understand this type of motion
we must breakup the velocity
into horizontal and vertical parts (components)

Finding Initial Horizontal & Vertical Components (parts)

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V - velocity of projectile fired

V_ix - initial V in x direction

V_iy - initial V in y direction

Use Trig. to Find V_ix and V_iy

Since…

COSӨ = A/H = V_ix/V

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CROSS MULTIPLY:

Initial Horizontal
Component of Velocity

V_ix = VcosӨ
(on reference table)

Since…

sinӨ = Opp./Hyp. = V_iy/V

CROSS MULTIPLY:

Initial Vertical
Component of Velocity

V_iy = VsinӨ
(on reference table)

During the times the ball is in the air,
how many times is the vertical velocity zero?

A bouncing ball captured with a stroboscopic flash at 25 images per second.

MichaelMaggs Edit by Richard Bartz

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2 times / At the Peak

Ex) A baseball is thrown upward at an angle of 30.° and a velocity of 6.0 m/s.

Find the initial horizontal & vertical components of the baseball's velocity.

Vertical Component

V_iy = VsinӨ

=(6.0 m/s)sin30.°

V_iy = 3.0 m/s up

Horizontal Component

V_ix = VcosӨ

= (6.0 m/s)cos30.^°

V_ix = 5.2 m/s across

3. Other Important Facts

d_x = V_xt

(memorize)

a_y = -9.8 m/s²
Ascending (down -)

a_y =+9.8 m/s²
Descending
(down +)

V_y at Peak = 0

Angles and Ranges

What angle produces the greatest range?

PelletierPhysics

45 degrees

Projectile Range

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Don Ion

Name another angle
that will give the same range (d_x)

55 degrees

35 degrees

65 degrees

25 degrees

55 degrees

35 degrees

20 degrees

70 degrees

Minimum Range

0°, 90°

Maximum Range

45°

Angle with Longest
Time in Air?

90 degrees

Angle & Components

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Ex) Which angle of projection causes a projectile to stay in the air longer?

50 or 70 degrees?

70 degrees,

(closest to 90,
longer time in air)

Ranking Task

1. A rock is thrown at various angles but with the same initial velocity.

2° 70° 20° 5° 60°

Rank the angles above from smallest horizontal displacement (dx) to the greatest

Projectile at an Angle
- Word Problems

[AP]