Includes references to PS#3-1 and 4-1 3. Describing Motion Includes references to PS#3-1 and 4-1

Picturing Motion Motion diagrams Ticker Tape illustrating constant velocity * * * * * * * * * * * * * * * * * * Ticker Tape illustrating constant acceleration * * * * * * * * * * *

Picturing Motion Motion Diagrams Vectors illustrating constant velocity Vectors illustrating constant acceleration ---> ---> ---> ---> ---> ---> ---> ---> ---> ---> ---> ---> ---> -> --> ---> ----> -----> ------> -------> --------> --------->

Speed, Distance, Time Speed is a scalar quantity. A quantity that has only magnitude. (a number plus a unit) For example: 10 mi/h, 12 km/h, 5 m/s Average Speed: The ratio of the total distance divided by the time. Average Speed = distance / time

Velocity, displacement, time Velocity is a vector quantity. A quantity that has both magnitude and direction. (A number, a unit, and a direction) For Example: 6.5 m/s, East Average Velocity: The ratio of the change in position to the time interval during … v(ave) = displacement / time displacement = d(f) - d(i) OR d - d(o)

Acceleration, /\v, time Acceleration is a vector quantity. A quantity that has both magnitude and direction For Example: 12 mi/h/s, East and +3 m/s/s which means 3 m/s/s forward Average Acceleration: The change in average velocity divided by time Acceleration = /\v / t And /\v = v(f) - v(i) OR v - v(o)

What’s up with m/s/s? A unit of acceleration is a change in velocity (I.e. m/s) divided by time (I.e. s) When a fraction like m/s is divided a value like s, the rule says to invert and multiply So a unit like m/s/s may be written as m/s^2, where the m/s is being divided by the second, and because of the invert and multiply rule for fractions its m/s^2

Working with PS#3-1 Let s represent speed, v(ave) may be used 1a-e, s = d / t 2a-e, d = s * t 3a-e, t = d / s 4a-e, v(ave) = d / /\t, bold type = vector 5a-e, /\t = d / v(ave) 6a-e, d = v(ave) * /\t

Working with PS#4-1 1a-e, a(ave) = /\v / /\t 2a-e, /\v = a(ave) * /\t 3a-e, /\t = /\v / a(ave) 4a-e, a(ave) = [v - v(o)] / /\t 5a-e, v = a * /\t + v(o) 6a-e, v(o) = v - a * /\t