Summer Physics Bootcamp
Instructor: Jeff Ciaccio, BS, BSChE,
MS, MSACS
“Jeff”, “Mr Jeff”, “Mr C”, “Ciaccio”
(See-ah-co) are all fine
Contact Information
• www.MSEAcademics.com
• Cell:770-401-6731
Jeffcia@MSEAcademics.com
Warm up
• You walked 0.5 miles north, 1.2 miles
west, 0.8 miles south, and 1.6 miles
east.
• find the total distance traveled (is this
a scalar or vector?)
• find the vector showing where you
ended relative to where you began.
Warm up
Warm up
Warm up
So, how far north/south, and how far east/west?
Use Pythagorean Thm and SOH CAH TOA
Warm up
Can you see this is exactly the same vector even
though the triangle has been drawn differently?
(0.4mi)2 + (0.3mi)2 = c2 = 0.25 mi2 so the
magnitude (length) = 0.5 miles
Distance and Displacement
Distance and Displacement
• Find the slope for each of the three
areas of the following graph. Include
the units and the sign. Describe what
happened in the three different
sections including speed and
direction.
• Find the average speed and velocity
for the whole time.
Eastward Position
(m)
Distance and Displacement
2.5
2
1.5
1
0.5
0
0
4
8
12
16
20
Time (s)
24
28
32
36
Distance and Displacement
• Find the slope for each of the three
areas of the following graph. Include
the units and the sign. Describe what
happened in the three different
sections including speed and
direction.
• Find the average speed and velocity
for the whole time.
Northward Position
(m)
Distance and Displacement
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0
8
16
24
Time (s)
32
40
Know the definitions!!
• There are several definitions that you must
know very well! Displacement, distance,
speed, velocity, acceleration, slope.
• There are also several that are more subtle:
vi, vf, vavg, Dv, etc.
• Physics is NOT about just finding the right
equation!! It is NOT a math class!
In your own words…
• On paper, write what you think acceleration
is.
• What do you think the units for acceleration
are (several correct answers).
• Hint: if you are at a red light, and then you
accelerate, what are you doing?
• Try to think of different ways you can
accelerate.
Acceleration
• acceleration is a vector. That means that it
can be positive, negative, and it has a
direction.
• acceleration: the rate of change in velocity.
• a = Dv/t
• If something is changing direction, it is
accelerating (even if the speed is not
changing).
Displacement: Easy case
• If you drive at a constant 50mph north for
30min, find your displacement and distance
traveled.
• Always, always, always check to make sure
units are consistent. Or even better, use
them in your equations.
Displacement:Easy case
60
50
40
30
20
10
0
Northward Velocity
(mi/hr)
Northward Velocity
(mi/hr)
• If you drive at an average of 50mph north
for 30min, find your displacement and
distance traveled.
0
10
20
Time (min
30
120
100
80
60
40
20
0
0
10
20
Time (min
30
Displacement:Easy case
60
50
40
30
20
10
0
Northward Velocity
(mi/hr)
Northward Velocity
(mi/hr)
• Find the area under both “curves”. And yes,
a straight line is called a curve. 
0
10
20
Time (min)
30
120
100
80
60
40
20
0
0
10
20
Time (min)
30
Average Vel: Easy Case
• If the acceleration is CONSTANT then
(and only then) can you can find
• This is the case 99% of the time even in a
calculus based class.
Neg in physics
• A negative sign in physics almost always
means the opposite direction.
• A negative acceleration does NOT mean
something is slowing down!!
• On your paper: You are going 5m/s to the
west and accelerating at 1m/s per second.
What is your velocity after 10 s? Make east
the positive direction.
see www.physicsclassroom.com/mop
Common Misconceptions
(On your paper, List all that apply)
• Can an object be moving upward with a
downward acceleration?
• If you throw an object straight up, what is
it’s velocity at the peak height? it’s
acceleration?
• Name 3 controls in a car that cause it to
accelerate
• If an object is accelerating, what MUST be
true?
Common Misconceptions
(On your paper)
• If an object is accelerating, what MIGHT it
be doing?
• If an object is NOT accelerating, it MUST
be: a) maintaining a constant vel, b) be at
rest, c) moving at constant, non-zero, speed
d) changing direction
• A car is moving to the west at 40mph and
slowing to 30mph. Its acceleration is (be as
specific as possible)
Common Misconceptions
(On your paper)
• A car is moving to the west (take east to be
the positive direction) at 10m/s. If it
accelerates at -bb2m/s per second for 10s,
what is its velocity? What is its speed?
• A car’s velocity after each consecutive
second is 2m/s, 4m/s, 6m/s, 8m/s, etc. This
car is moving with a constant __________.
Common Misconceptions
(On your paper)
• A car moving at a constant velocity of
10m/s east for 5 seconds has an acceleration
of _________.
• A car moving at 20m/s west, then 18m/s
west after 2 seconds has an acceleration of
_________. (A positive direction has NOT
been established).
Common Misconceptions
(On your paper)
• Which are units of acceleration?
(m/s)/s
m/(s s)
m/s2
(m/min)/s
mph/s
m/s
mi/s
all of these?
Common Misconceptions
(On your paper)
• a car with rightward velocity and leftward
acceleration is moving in which direction
and speeding up/slowing down.
The “Big 4”
Dd
Vavg * t
Dv
a
Dd = vit + ½ at2
vf2 = vi2 + 2aDd
*
t
Use them in the order
presented
• You can use any equation as long as
there is only 1 unknown.
• Watch your UNITS!! Units must be
consistent to cancel them out.
• Watch for vectors that must be broken
into their componenets
• Try to use the equations in order
Fill in the table
• Write the table this way
a
vi
vf
vavg
Dv
Dd
t
1 Dimensional Examples
• If you travel at an average of 10m/s
for 2 min, how far will you have
gone?
• The only things we know are vavg and
t.
• Convert units first: t = 120s
1 Dimensional Examples
a
vi
vf
vavg
Dv
Dd
t
0
Dd
Vavg * t
10m/s
120 s
Cover up the Dd, which shows you
to multiply vavg and t.
10m/s * 120s = 1200m
Use your dimensional analysis just
like in chemistry!! Cancel the s’s
1 Dimensional Examples
• A ZX6 accelerates from rest to 20m/s
in 3.0s. Find the acceleration and the
distance.
• All units are consistent with each
other
1 Dimensional Examples
a
vi
vf
vavg
Dv
Dd
t
0
20m/s
10m/s
20m/s
3s
Dd
Vavg * t
Dv
a
*
t
We have enough information to use
the first both magic triangles.
Notice that the avg vel is just 0 + 20
over 2 and delta v is vf – vi
Delta d = 10m/s * 3 s = 30m
a = Dv/t = ( 20m/s ) / (3 s) =
6.67m/s2
1 Dimensional Examples
• An F-22 Raptor accelerates at 5m/s2
from 20m/s to 120m/s. How long did
it take, and how far did it go?
1 Dimensional Examples
a
vi
vf
vavg
Dv
Dd
t
5m/s2
20m/s
120m/s
70m/s
100m/s
Dd
Vavg * t
Dv
a
*
t
We don’t have enough information
to use the first magic triangle, but we
can solve for time with the second
and then go back to the first.
t = Dv/a = 20s
Dd = vavg * t = 70m/s * 20s = 1400m
1 Dimensional Examples
• An F-22 Raptor accelerates from
20m/s to 120m/s in 1000m. How long
did it take, and what was its
acceleration?
1 Dimensional Examples
a
vi
vf
vavg
Dv
Dd
t
20m/s
120m/s
70m/s
100m/s
1000m
Dd
Vavg * t
Dv
a
*
t
We can use the first magic triangle to
find time and then the second to find
acceleration
t = Dd/ vavg = 1000m/70m/s = 14.29s
a = Dv/t = ( 100m/s ) / (14.29s) =
7m/s2
Gravity and little g
• Gravity is a FORCE.
• Objects with more mass will have a
greater gravitational force (weight)
• Objects near the surface of the earth
will ACCELERATE at a constant
9.8m/s2. This is “g” the acceleration
due to gravity. NOTE: This is NOT
“gravity”
Gravity and little g
• g will be different on different
planets/moons/locations.
• g is slightly different at sea level or on a
mountain top, but it is very slight, so most
teachers will allow you to use 9.8m/s2 (or
even 10m/s2 sometimes)
• g is negative ONLY because we normally
take up to be the positive direction.
1 Dimensional Examples
• You are on a cliff that is 100m above
the ground when you throw a rock
straight up at 12m/s. How long will it
take to reach the peak (hint what is
vpeak?). How high above the ground is
that? How long would it take to reach
the ground from the peak? What is
the total time it spent in the air?
Up to peak
a
vi
vf
vavg
Dv
Dd
t
-9.8m/s2
12m/s
0m/s
6m/s
-12m/s
Dd
Vavg * t
Dv
a
*
t
We can use the second magic
triangle to find time and then the
first to find distance from the cliff.
t = 1.224s Dd = 7.35 m
Down from peak
a
vi
vf
vavg
Dv
Dd
t
-9.8m/s2
0
-107.35m
We finally get to a case where we
need the 3rd equation
Dd = vit + ½at2 and since vi = 0
Dd = ½at2
Breaking up Problems
Notice that we broke up the last problem into
i) Up to the peak
ii) Down from the peak
This is a great strategy, but you must keep everything
straight! Do NOT do things blindly in physics!!
This can often make the math easier (like avoiding
quadratic equations with linear terms).
Minds On Physics
• I highly, HIGHLY recommend that you
use Minds On Physics to test your
conceptual understanding before going
on to more advanced problems.
• www.physicsclassroom.com/mop
• For tonight, try those in
Mechanics>Kinematic Concepts