bellwork what are projectiles? *** turn in projectile lab *** they are objects where gravity and air...
TRANSCRIPT
BellworkBellwork
• What are projectiles?
*** Turn in “Projectile Lab” ***
• They are objects where gravity and air resistance are the only forces acting
Projectile Motion IIProjectile Motion II
10/2/1310/2/13
ComponentsComponents
• Component: the projection of a vector quantity along a perpendicular axis
ComponentsComponents
Horizontal
• Right = +x
• Left = -x
Vertical
• Up = +y
• Down = -y
Projectile QuantitiesProjectile Quantities
• Displacement (m)
dx = horizontal displacement
dy = vertical displacement
• Velocity (m/s)
vx = horizontal velocity
vy = vertical velocity
Projectile QuantitiesProjectile Quantities• Acceleration
ax = 0 m/s2 (no horizontal acceleration)
ay = -9.81 m/s2 or “g”
• Time (s)
t = time
- Does not depend on direction (scalar)
- It is the same for horizontal and vertical components
Projectiles and TimeProjectiles and Time
• (i.e.) A projectile has the same time for how long it goes up and/or down AND left or right
Quantity HorizontalComponent
Vertical Component
DisplacementYes,
same distanceeach second
Yes, different
distances each second.
VelocityYes,
ConstantYes, changing by -9.81 m/s each second.
Acceleration NoYes, constant
9.81 m/s/s, downward
“g”
Notes End Here
Projectile Example
• What happens to a projectile’s horizontal and vertical displacement, velocity and acceleration?
• Example: An object with a initial horizontal velocity of 20 m/s to the right and vertical velocity of 0 m/s.
Displacement
Time HorizontalDisplacement
VerticalDisplacement
0 s 0 m, right 0 m
1 s 20 m, right 5 m, down
2 s 40 m, right 20 m, down
3 s 60 m, right 45 m, down
4 s 80 m, right 80 m, down
5 s 100 m, right 125 m, down
Velocity
Time HorizontalVelocity
VerticalVelocity
0 s 20 m/s, right 0 m/s
1 s 20 m/s, right 10 m/s, down
2 s 20 m/s, right 20 m/s, down
3 s 20 m/s, right 30 m/s, down
4 s 20 m/s, right 40 m/s, down
5 s 20 m/s, right 50 m/s, down
Acceleration
Time HorizontalAcceleration
VerticalAcceleration
0 s 0 m/s/s 10 m/s/s, down
1 s 0 m/s/s 10 m/s/s, down
2 s 0 m/s/s 10 m/s/s, down
3 s 0 m/s/s 10 m/s/s, down
4 s 0 m/s/s 10 m/s/s, down
5 s 0 m/s/s 10 m/s/s, down
A falling object
A falling object
Projectile (Horizonal)Projectile (Horizonal)
Projectile (Launched)Projectile (Launched)
Next LabNext Lab
• You will be able to calculate the horizontal velocity
• From this you will make a calculated prediction where it will land on the floor
Formula CardsFormula Cards
• Component axis
• Horizontal vs. Launched
• Projectile y-component
• Projectile x-component