d, v, a - Problems Mdcl1 Mdcl! Mdcl1 Mdcl! Outline Predicting future velocities Complete Motion Diagram

QQ7 Av Speed Quick Quiz An athlete swims the length of a 50m pool in 18s and then makes the return trip to the starting position (which is x=0) in 20s. Determine his average velocity for the entire swim: (A) 0 m/s (B) 2.5 m/s (C) -2.5 m/s (D) -5 m/s

Predicting Motion   Who has seen these formulae before? DST tri. V2=v1+at Who has seen these formulae before? DST tri. V2=v1+at

Eg: You drop a rock from a tall building from rest. If the rock falls down with an acceleration of a = -10m/s 2 a) how fast will it be moving after 10 s? b) what will the acceleration be after 10 s ?

Complete Motion Diagrams Dots represent positions at uniformly spaced time intervals An arrow that connects two dots represents the direction and relative magnitude of the average velocity for the time interval between those two dots Arrows drawn at the dots represent the average acceleration for the time interval between the previous dot and the next dot

Eg: Motion Diagram A penny is dropped off of the observation deck at the CN tower. Draw a complete motion diagram which depicts its motion from the instant it starts to fall, until the instant before it hits the ground.

Eg: Motion Diagram A ball rolls along a path as shown in the following diagram: The ball rolls at constant speed on the level surfaces, except for the period where it is going up the ramp. Draw a complete motion diagram which depicts the balls motion.

Eg: Motion Diagram A plane flying North at 300 km/h slowly turns to the East without changing speed. Draw the complete motion diagram which depicts the planes motion. Remind them that proper subtraction of velocity vectors will always give them the correct direction of acceleration. Even if the plane were accelerating or decelerating during its turn.

Eg: Motion Diagrams A car is accelerating for the first 3 seconds, then it moves at a constant speed for the next 3 seconds, and finally decelerates for the last 3 seconds. What would the motion diagram look like?