Transcript Physics 121 Fall 2002

Common exam
Common Exam 1
Exam graded out of 16 problems so 2 problems are
‘extra credit’
Average (sections 14 and 16): 12.13
- mid-range B
Low – 5
High – 18
Estimated grades posted. LOTS of A’s, mostly B and
above.
A few F’s…… Generally, these students are not doing
1
HW assignments
More Tutoring Available
TA: Phil Lo, [email protected]
FRIDAYS 11:30-2:30pm ROOM 409 Tiernan
MONDAYS 2:30-5:30pm Room 409 Tiernan EXCEPT
weeks that we have common exams.
the Saturday BEFORE the exam from noon-3pm, also
in Room 409Tiernan.
Undergraduate TA: Lucas Lamb, [email protected]
Mondays Noon-2pm and Thursdays 10AM-1pm in
Tiernan 401
Undergraduate TA: Griffin Snyder
sunday from 6pm-9pm - TBA
Tuesday 10am-2pm
- TBA
Wednesday 9am-12pm – 409 Tiernan
Iclicker Question #1
If these movable masses connected through a pulley (pulley and incline
surface are frictionless), what condition should be applied if the masses
are in equilibrium?
A)
B)
C)
D)
E)
The acceleration of m1=0
The acceleration of m1 is equal to the acceleration of m2
The masses do not move at all
The masses move with the same constant speed.
Is this going to be on the exam?
Iclicker Question #2
Under what condition will mass m2 move UP the incline.
A)
B)
C)
D)
E)
m1  m2
m1  m2
m1  m2 sin 
m1  m2 sin 
m1  m2 sin 
Origin of Friction
Static versus Kinetic Friction
Iclicker Question #1
You push and hold a book against the wall. Which of the following free
body diagrams represents the forces acting on the book:
(e)
(a)
(c)
(b)
(d)
Iclicker Question #2
Based on the following free body diagram, which of the following
statements is correct?
A) The block is moving up the incline
B) The block is moving down the
incline
C) The block is not moving
D) The block is sliding at constant
velocity up in the incline
E) None of the other answers are
correct
N
f
mg
Friction forces in liquids
Circular Motion
Conical Pendulum
Conical Pendulum
40
30
sin ( ) 20
cos( theta)
cos(( ) ) 10
2
sin2 thetai
i
0
0
20
40
60
80
100
i
Angle (degrees)
As velocity of mass increases, angle
increases, and pendulum mass increases its
radius of orbit.
Iclicker Question #3
Why are the turns of highway roadways banked?
A)
B)
C)
D)
To increase the force of friction of the tires on the road
To increase the weight of the car on the road
The civil engineers were bored with flat road designs
To increase the centripetal force which pushes the car in a circular
path
E) To decrease the weight of the car on the road
Friction on a Flat Road
Centripetal versus centrifugal forces
Banked Curve
Iclicker Question #4
Which is the following is the fastest roller coasters in the world?
A) El Toro at Six Flags Great Adventure (US)
B) Top Thrill Dragster at Cedar Point (US - Ohio)
C) Dodonpa at Fuji-Q Highland (Japan)
D) Kingda Ka at Six Flags Great Adventure (US – New Jersey)
E) Formula Rossa at Ferrari World (United Arab Emirates)
Iclicker Question #4
Which is the following is the fastest roller coasters in the world?
A) El Toro – 70 mph (fastest wooden roller coaster)
B) Top Thrill Dragster – 120 mph
C) Dodonpa – 107 mph
D) Kingda Ka - 128 mph
E) Formula Rossa - 149 mph