AP Physics
Monday 14.01.27
Standards: D3a5Analyze
situations in which two or more
objects are pushed apart by a
spring or other agency, and
calculate how much energy is
released in such a process.
Warm Up
A 5000 kg freight car moving at 4
km/hr collides and couples with
an 8000 kg freight car which is
initially at rest. The approximate
common final speed of these two
cars is…
a) 1km/hr b) 1.3 km/hr c) 1.5
km/hr d) 2.5 km/hr e) 4 km/hr
Objective: SWBAT solve AP Free
Response Problems on
momentum.
Agenda
1. Warm Up
2. Collect Homework M5-M8
+Extra
3. Guided Practice AP Free
Response.
Homework
Momentum Test Wednesday
Homework #M9
AP Physics
Tuesday 14.01.28
Standards: D3a5Analyze
situations in which two or more
objects are pushed apart by a
spring or other agency, and
calculate how much energy is
released in such a process.
Objective: SWBAT compete for
extra credit to solve AP
Momentum Problems as a test
review.
Agenda
1. Warm Up
2. Test Review
Warm Up
If the unit for force is F, the unit
for velocity is v and the unit for
time t, then the unit for
momentum is
a) Ft b) Ftv c) Ft2v d)Ft/v e)Fv/t
Homework
Review for Test
AP Physics
Wednesday 14.01.29
Standards: Momentum Test
Objective: SWBAT score at least 40% (AP
4) on the test.
Warm Up
A mass m has speed v. It then collides
with a stationary object of mass 2m. If
both objects stick together in a
perfectly inelastic collision, what is the
final speed of the newly formed
object? a) v/3 b) v/2 c) 2v/3 d) v e)
3v/2
Agenda
1. Warm Up
2. Momentum Test
Homework
Test
AP Physics
Thursday 14.01.30
Standards: Relate the radius of a circle
and the speed or rate of revolution of the
particle to magnitude of centripetal
acceleration.
Objective: SWBAT will be to solve
centripetal motion problems.
Agenda
1. Warm Up
2. Review Test
3. Centripetal Motion Notes
4. HW C#1
Warm Up
An elastic collision occurred
between two masses. Set up the
conservation of momentum
equations for this scenario and
solve for the final velocity of mass
#2.
Homework
C#1
AP Physics
Friday 14.01.31
Standards:
Relate the radius of a circle and
the speed or rate of revolution
of the particle to magnitude of
centripetal acceleration.
SWBAT determine a value of
the acceleration due to gravity
by experimenting with
centripetal motion.
Agenda
1. Warm Up
2. Review HW
3. Lab
4. AP Lab FRQ
Warm Up
8. A child has a toy tied to the end of a
string and whirls the toy at constant speed
in a horizontal circular path of
radius R. The toy completes each
revolution of its motion in a time period T.
What is the magnitude of the
acceleration of the toy?
(A) Zero (B) 4π2R/T2 ( C ) πR/T2 (D) g (E) 2πg
Hint: this problem requires 2 of the 3
equations we learned yesterday.
Homework
C#2
Lab Report Due Tuesday
AP FR Guided Practice
A massless spring is between a 1-kilogram mass and a 3-kilogram
mass as shown above, but is not attached to either mass. Both masses
are on a horizontal frictionless table. In an experiment, the 1-kilogram
mass is held in place and the spring is compressed by pushing on the
3-kilogram mass. The 3-kilogram mass is then released and moves off
with a speed of 10 meters per second.
• a. Determine the minimum work needed to compress the spring in
this experiment.
In a different experiment, the spring is compressed again exactly as
above, but this time both masses are released simultaneously and each
mass moves off separately at unknown speeds.
• b. Determine the final velocity of each mass relative to the cable
after the masses are released.
M#9 FRQ Practice
• A bullet of mass m and velocity vo frictionless horizontal surface. The
bullet penetrates the block and emerges with a velocity of is fired
toward a block of mass 4m. The block is initially at rest on a 3vo
• (a) Determine the final speed of the block. vf2=vo/6
• (b) Determine the loss in kinetic energy of the bullet. ΔK=(4/9)mvo2
• (c) Determine the gain in the kinetic energy of the block.K=(1/18)mvo2
Centripetal Motion Guided
Practice
4b Pat Kinch used a racing cycle to travel 75.57 km/h. Suppose
Kinch moved at t his speed around a circular track. If the
combined mass of Kinch and the cycle was 92.0 kg and the
average centripetal force was 12.8 N, what was the radius of the
track? r=3.17x103m
Centripetal Motion C#1
A. Fc=?
m=20kg
r=40m
v=5m/s
1.
2.
B. Fc=40N
m=4kg
r=40m
v=?
C. Fc=40N
m=2kg
r=6m
T=?
(A6)In 1995, Cathy Marsal of France cycled 47.112 km in 1.000
hour. Calculate the magnitude of the centripetal acceleration of
Marsal with respect to Earth’s center. Neglect Earth’s rotation,
and use 6.37x103 km as Earth’s radius.
(B5) In 1992, a team of 12 athletes from Great Britain and Canada
rappelled 446 m down the CN Tower in Toronto, Canada. Suppose
an athlete with a mass of 75.0 kg, having reached the ground,
took a joyful swing on the 446 m-long rope. If the speed of the
athlete at the bottom point of the swing was 12 m/s, what was
the centripetal force? What was the tension in the rope? Neglect
the rope’s mass.
Centripetal Motion Lab
Objective: Create a graph whose slope is acceleration due to gravity
and is equal to g. Compare this value to g=9.80 m/s2 using % error.
r
1. Write a procedure.
m1
2.. Fill in the table below:
Trial
mball
mclip
(kg)
(kg)
mw
(kg)
total
time
(s)
# rev
T(s)
rstr+ba
v
ll (m)
(m/s)
F(N)
v2/r
(m/s2)
1
2
3
3. Graph F vs. v2/r (the right 2 columns), find the best fit line,
the slope, and the equation of the line.
F(N)
binder clip
m2
mtotal (kg)
4. slope = acceleration due to gravity of the ball, so we will compare the acceleration due to
gravity with our measured value to find its accuracy
g
-g
%error =|
actual
measured
gactual
| x100%