1. Honors Physics Chapter 2 Kinematics in One Dimension
Kinematics – deals with concepts describing motion
Dynamics – deals with the effects that forces have on motion
Mechanics – Kinematics and Dynamics make up the branch of physics called Mechanics
Displacement: It is a vector showing the initial position and final position of an object. (SI unit: meter)
Velocity is speed + direction
A plane flies at 100 mph from Minneapolis
To Chicago (a distance of 325 miles). How
Long will the flight take to get there?
3250 minutes
.31 hours
3 hours and 15 minutes
3 hours and 25 minutes
2 hours and 45 minutes
Speed = distance
time

2. Kinematics One Dimension
Average Velocity = displacement / elapse time or total distance / total time
Instantaneous Velocity = Your speed and direction at any given moment in time.
The space shuttle travels at 7,600 m/s. You start and stop a stopwatch as quickly as you can and get .05 sec. About how many football fields (96m) can the space shuttle travel in the time it takes you to start and stop a stopwatch?
A) 1 B)2 C) 3 D) 4 E) 5 F) 8 G) H) 14

3. Acceleration If you can “feel it” it’s acceleration
It is the rate of change in velocity
Speeding up, slowing down, changing direction
It is how much is your speed changing each second
meters / seconds / second
m/s2
Acceleration = Vfinal – Vinitial
time
If a baseball goes from 0 – 50 m/s
In half a second. What is the acceleration
Of the baseball?
100 m/s2
0 m/s
200 m/s2
100 m/s
125.5 m/s2

4. 10 m/s B) -25 mi/hr/sec C) 25 mi/hr/sec
A car on the highway is going 50 miles/hr and passes another car and reaches a top speed of 75 mi/hr 5 seconds after beginning the pass. What is the rate of acceleration of the car?
10 m/s B) -25 mi/hr/sec C) 25 mi/hr/sec
D) 5 m/s2 E) 5 mi/hr/sec F) 10 m/s2
A car going 20 m/s (about 45 mph) is put into neutral and coasts to a complete stop. You have an accelerometer in the car and it shows you are decelerating at a rate of - 2 m/s2. How long does it take for the car to slow down to a speed of 10 m/s (22 mph)?
A)1 sec B) 2 sec
C) 5 sec D) 10 sec E) 40 sec

5. Gravity Galileo Galilee –
Experimented with dropping different massed objects off the Tower of Pisa.
All objects fall at the same rate, regardless of mass – 9.8 m/s2
Isaac Newton – He did experiments that showed all
Things with mass have gravity.
Anything with mass has a gravitational pull
The larger the MASS of an object, the larger the gravitational pull
The closer you are, the greater the “g”

6. Gravity Albert Einstein –
Explained why there is gravity through his ideas of space and time.
Objects with mass bend the “fabric” of space/time and create an attraction of other objects.

7. Motion is relative Anything in motion has a right to say it is at rest
It depends on your frame of reference

8. Calculating Free Fall How fast an object is falling:
Velocity = Gravity x Time
v = gt
How far an object falls:
Distance = ½ gt2
You are standing on top of your 6 meter spaceship on the moon (gravity: 2 m/s2). You drop something off the spaceship. How long does it take to hit the ground?
A) .5 s B) 1 s C) 1.5 s D) 2 s E) 2.5 s F) 3 s

9. A penny is dropped from the top of the IDS Tower in Minneapolis (236 m). A penny is also dropped from the Sears tower in Chicago (442 m). Ignoring air resistance, how much faster is the penny dropped from the Sears Tower going when it hits the ground than the IDS tower penny.
Sears Tower
12.4 m/s
25 m/s
68 m/s
93 m/s
164 m/s
212.4 m/s
I don’t know how to solve this
IDS Tower

10. How fast an object is going with an initial velocity is expressed as:
If an object has in initial velocity going up or down as it goes into freefall, the equation changes just a little.
How fast an object is going with an initial velocity is expressed as:
Velocity = Velocityinitial + gravity x time
V = V0 + gt
A ball is thrown upward at 15 m/s. How fast is it going after 2 seconds?
4.6 m/s B) -4.6 m/s
C) neither of these

11. How far an object goes that has an initial velocity is expressed as
Distance = Velocityinitial x time + ½ gravity x time2
d = V0t + ½ gt2
A ball is thrown upward at 15 m/s. How high is it after 2 seconds?
About…
5m B) 8m C) 10m D) 12 m

12. Kinematic Equations
The equations used for freefall can also be used in lateral motion, substituting “g” for whatever acceleration is present.
In summary, these equations can solve any straight line motion:
V = V0 + at
X = ½ (V0 + V) t
X = V0t + ½ at2
V2 = V02 + 2ax

13. Air resistance Responsible for changes in rates of falling objects
A form of friction that gives off heat.
When air resistance is negligible, objects can be considered “free falling”

14. Motion graphs Which stage is the object stopped?
Where is the object accelerating?
What stage shows a
constant speed?
What would the graph
look like if the object
moved backward at
Stage 6?

15. Questions
Punter Chris Kluwe of the Vikings has a hang time of 4 seconds on a punt. How high does it go?
A) 10m
B) 20m
C) 30m
80m
160m
How long does it take for a water
Balloon to fall to ground from 15meters (about 5 stories)
A) 1.7 sec B) 3 sec C) .86 sec D) 4.7 sec

16. Questions
A rocket is launched upward and reaches a velocity of 200mph at the moment the engine quits. What is the approximate velocity of the rocket at 1 second after the engine went out (#2)?
0 mph
198 mph
200 mph
202 mph