1. Can you figure this out?
Two birds perched directly next to each other, leave the same tree at the same time. They both fly at 10 km/h for one hour, 15 km/h for 30 minutes, and 5 km/h for one hour. Why don’t they end up at the same destination?

2. visuals taken from: http://www.amazing-animations.com/
Velocity
the rate of change of an object’s position
speed in a given direction
is considered constant when speed and direction do not change
changes as speed or direction changes
is a vector
can be combined (added if moving in the same direction and subtracted if moving in the opposite direction)
i.e. – If you are walking at a rate of 1.5 m/s up the aisle of an airplane that is traveling north at a rate of 246 m/s, your velocity would actually be m/s
29 m/s east
25 m/s west
visuals taken from:

3. Vector a quantity that has both direction and magnitude (size)
drawn as an arrow which shows direction and magnitude (length of arrow)
consists of two parts: tail and head
Head
Tail
Consider the vectors above. Describe the direction and relative magnitude (speed) of each car based on the vector.

4. Three airplanes are coming in for landing
Three airplanes are coming in for landing. Given that they are all going 200 mph, how would velocity be useful in determining where and when they could each land?
The wind is blowing at 12 mph. A group of skydivers are attempting to jump from a plane. How would the velocity of the wind or the airplane be useful in determining where the skydivers should jump from?
If the police are chasing a runaway car, why is the velocity of the car important information to have?

5. DO NOW
One person from each group get a box of calculators for your group.
Calculate the following in your notebooks:
How long would it take a deer traveling at 2.5 m/s to cross a road that is 15 m wide?
How far did the lion travel to catch its prey if it was traveling at m/s and caught the prey after 60 s?

6. Explain how both cars are accelerating.
Acceleration
the rate at which velocity changes
occurs when something is speeding up (+), slowing down (-), or changing direction
Formula:
typically expressed in units of m/s2
is always changing, and considered centripetal, when traveling in a circle
a = vf – vi t
Explain how both cars are accelerating.

7. Acceleration in the same direction as the motion
Object’s speed increases
(accelerate, positive acceleration)
Acceleration in the opposite direction of motion
Object’s speed decreases
(decelerate, negative acceleration)
Acceleration at a right angle to motion
Object speed does not change
direction of motion changes

8. Practice Problems - Acceleration
Tina starts riding her bike down a hill with a velocity of m/s. After six seconds, her velocity is 14 m/s. What is Tina’s acceleration?
2. A motorcyclist goes from 35 m/s to 20 m/s in five seconds. What was his acceleration?
a = vf – vi t
14 m/s -
2m/s
2 m s2
a = =
6 s
a = vf – vi t
a =
20 m/s -
35 m/s
-3 m s2 =
5 s

9. Describe the student’s acceleration as she travels to class?
Velocity-Time Graph
Shows how acceleration relates to velocity and time 50 40 30 20 10 60 70 80 90
100
Time (seconds) 2 4 6 8 12
Velocity (meters/second)
This velocity-time graph will show a student’s acceleration as she returns to class after lunch.
Describe the student’s acceleration as she travels to class?