EVERYTHING IS MOVING!!! Halloween Edition

Linear Motion Motion is Relative – there is no place in the universe that isn’t moving, so we must state motion “relative” to something else.

Linear Motion Reference Frame – the spot designated “not moving”… all motion is described relative to it (usually the ground). Sometimes we will assign other places as reference frames. This changes the relative motion of ALL other objects.

Speed A measure of distance covered in a time period, or how fast it is moving. S= d/t Ex. A car moves 60km in 3 hrs, it has a speed of 20km/hr distance

S= d/t Speed Which has a > speed? Why? Same distance < time

Speed: Types Instantaneous Speed – how fast an object is moving at an “instant” of time. Ex: Speedometer Average Speed = total distance/ total time

South Speed vs. velocity V , velocity is a measure of distance covered in a time period, or how fast it is moving with a direction. V = d/t Ex. A witch that moves 60km North in 12 hrs has a velocity of: West East 5km/hr North North

Constant vs Changing Velocity

How many accelerators in the car??? Acceleration Δ (delta) means “change” How many accelerators in the car??? Δ Velocity Δ time Objects accelerate anytime their speed or direction changes.

Acceleration due to gravity (g) on Earth is about 10 m/s/s REGARDLESS OF WEIGHT!!! What falls faster, a bowling ball or pebble?

Free Fall How Fast? How Far? Bluh, Bluh, Bluh, I Vant To Suck Your Bluuuud! Time (s) Speed (m/s) Distance (m) 1 10 5 2 20 3 30 45 4 40 80 50 125 Equation t 10t ½ 10t2

Velocity d v t v = d/t d = vt t = d/v

Acceleration Δv a Δt a = Δv/Δt Δv = aΔt Δt= Δv/a

Distance (free fall) d t2 ½ a d = ½ at2 a = 2d/t2 t= √(d/½ a)

Equations (pg 1) V =d/t d=Vt t=d/V a =ΔV/Δt ΔV =a Δt t= ΔV/a d=1/2at2 When velocity is constant: V =d/t d=Vt t=d/V When the object is accelerating: a =ΔV/Δt ΔV =a Δt t= ΔV/a d=1/2at2 Remember, gravity is an acceleration and can be substituted for a in any of the equations when gravity is doing the accelerating.

Constant Velocity Graphed Distance Time Graphs Constant Velocity Graphed

Distance Time Graphs #2 Acceleration Graphed

Ideal Models and Air Resistance Many examples will apply only in the “Ideal World” where air resistance/ friction doesn’t exist.

-10 m/s2 Speed & acceleration = Zero! +10 m/s2

4 s 0m/s -10m/s/s 3 s 10m/s -10m/s/s 2 s 20m/s -10m/s/s 1 s 30m/s -10m/s/s 0 s 40m/s

Baseball ends up in his hand! 0m/s +10m/s/s 5 s -10m/s +10m/s/s 6 s -20m/s +10m/s/s 7 s -30m/s Baseball ends up in his hand! +10m/s/s 8 s -40m/s

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