Post on 20-Jan-2022
Projectile MotionIB PHYSICS | MOTION
Reminder of our Equations
Units m m s-1 m s-1 m s-2 s
π£ = π’ + ππ‘ π’ π£ π π‘
π = π’π‘ + 12ππ‘2 π π’ π π‘
π£2 = π’2 + 2ππ π π’ π£ π
π = π£+π’ π‘2
π π’ π£ π‘
Dropping the Ball
How much time will it take this ball to hit the ground when
dropped? The impact velocity?
π -25 m
π’ 0 m s-1
π£ ?
π -9.81 m s-2
π‘ ?
25 m
π = π’π‘ + 12ππ‘
2
β25 = 12(β9.81)π‘2
π‘ = 2.26 s
π£2 = π’2 + 2ππ
π£ = 2ππ = 2(β9.81)(β25)
π£ = β22.2 m sβ1
Air Time - Comparison
Which ball will have more air time?10 m/s
The balls hit the ground at
EXACTLY the same time
Air Time - Comparison
Free Fall
Constant
Velocity
10 m/s
Horizontal Projectile
25 m
Vertical Only
π -25 m
π’ 0 m s-1
π£ -22.2 m s-1
π -9.81 m s-2
π‘ 2.26 s
How far does the ball travel?
From Previous Problem
π = π£π‘
π = 22.6 m
= (10 m sβ1)(2.26 s)
π£ =π
π‘
One Dimensional Motion
VerticalAccelerating
HorizontalConstant Velocity
[v = d/t]
Horizontal Projectile
Two-Dimensional Projectile
Same as the
horizontal projectile
Which one lands first??
A
B
Which one lands first??
B
A
Only vertical velocity and
height affects air time
Lesson Takeaways
β I can compare the motion of an object dropped from
rest and an object with an initial horizontal velocity
β I can calculate the air time and speed for a horizontal
projectile
β I can describe how the vertical and horizontal
components are independent from each other for a
projectileβs motion
β I can compare the air time for two projectiles given their
trajectories.