Physics 111 Common Exam 2 Supplemental Spring 2013, Version A
Name (Print): _
4 Digit ID:_ Section: _
Honors Code Pledge: For ethical and fairness reasons all students are pledged to comply with the
provisions of the NJIT Academic Honor Code. You must ans
Class 17-13
Conservation and Potential
Energy
1. Reminder about syllabus: This stuff is
officially in Exam 3, but Exam 2 is on
March 6.
2. Lets learn the conservation Concept now
3. Its similar to Work (exam 2)
Reminder about Syllabus
Week 3 Forces + exam
Class 16-16
Momentum and Impact
Your text here
Review
Quiz
Note: withdrawal by Monday Nov. 7
Conservation of Momentum: mv
(vector)
Kinetic energy conserver:
It bounces off: mv+MV=mv+MV
Kinetic energy lost:
It sticks: mv+MV=(M+m)v
It explodes: (M+m)vo=mv+M
15d spinning ninja
balls
Rotation
Question
A ninja swings the balls around by holding the one at one end. The
other two are at distances from her hand of 0.4 m and 0.5 m. Each ball
weighs 1kg. When she spins them at 6rad/s, what is the kinetic energy
in J
Question:
A motor moves an elevator, m=1000kg,
with no counter-weight, down with no
friction. When its speed is 3m/s, it slows
to a stop at the 3rd floor in a time 3s. A
woman scientist, with mass m=50kg, is
standing on a scale in the elevator to
study it
NJ Transit Train Question:
1. What is the tension in the coupler connecting the last 2
cars in the train? The train has 6 cars and is pulled by a
force of 30,000N. Each car has a mass of 5000kg.
Answer
A. Diagram:
B.
C.
D.
E.
D.
E.
F.
T(#6)=?;M=5000kg; N=
Class 17-12
Work and Energy and quiz
6 Work Quiz on Moodle
Goes live at 10:30 am Thurs. Feb 23
Ends 11:00 am
Work and kinetic energy
Here are 2 forms of energy:
m ax dx = (1/2)mv2- ()mv02
Comes from: 2ax = v2- v02
Work =F.d (the part in the same direction
Class 17-13
Conservation and Potential
Energy
1. Reminder about syllabus (This stuff is in
Exam 3) Exam 2 is on March 6.
2. Lets learn the conservation Concepts now
3. Theyre similar to work concepts (exam 2)
Reminder about Syllabus
Week 3 Forces + exam 1
Static Forces
Quick review: Newtons laws:
Inertia =total mass moving
F=net force (unbalanced)
F1=F2 (balanced)
Static Forces : vectors
Class 7
burglars:
On roof, M=100 kg.
Over side, m=50
kg. Static.
What is force of
friction?
What is a?
Vector review
A d
Forces: Burglars
New:
F= sum of all the
forces
a=F/(all the mass
that is moving)
Burglars falling
A burglar, M=120kg, sits on an icy
roof; another burglar, m=60kg, is
connected by a rope through a pulley over the side of a
building. M slips; m falls fo
An elevator with m=1000kg is at rest
at one of the floors 20m above the bottom.
Then, the cable supporting
it breaks and the elevator falls freely, but has
a counter weight, M=900kg.
During the fall, what is the tension
in the cable connecting
the 2 masse
Class 16-17
Circular Motion
Your text here
Introduction
Withdrawal: regular by Monday Nov. 7
Special by Nov. 17th
Motion in a circle with constant
speed
Key equations
Period:
T=time for a trip around
Frequency:
Circumference: c=2R = R
Speed:
v=2R/T = R
Ci
15e falling elevator
Rotation
Question
1. What is the angular acceleration of the pulley?
2. An elevator with no counter weight has its motor fail. The elevator
with mass 200kg falls 6m. It is slowed by the inertia of the big
pulley (solid disc, R=1m and
Physics 111 Common Exam 2 Supplemental Spring 2013, Version A
Name (Print): _
4 Digit ID:_ Section: _
Honors Code Pledge: For ethical and fairness reasons all students are pledged to comply with the
provisions of the NJIT Academic Honor Code. You must ans
Sample exam 2
1. A block is pushed across a horizontal surface by the force shown. If the coefficient of kinetic friction between the block and
the surface is 0.30, F = 20 N, = 30, and M = 3.0 kg, what is the magnitude of the acceleration of the block?
A)
Question:
Plane lands on an
aircraft carrier
Question 1:
A plane landing at 100m/s on an aircraft carrier catches
his tail hook on a special spring with spring constant
100,000N/m. The planes mass is 1000kg. How fast is
the plane moving after it has compr