Other Practice for Thermal Energy and Specific Heat
1. If 200 g of tea at 95C is poured into a 150 g glass cup initially at 25C, what will be
the final temperature of the tea when equilibrium is reached? Assume no heat flows to
the surrounding air.
cglass
Into which circuit should the battery be connected to obtain the greatest steady power
dissipation?
AB
C
DE
28. 1/1 points All Submissions Notes
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Submissions
1
1
1/1
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1/1
Which circuit will retain stored energy if the battery is c
This problem and the next are about the following situation. Two positive charges of
magnitude q are each a distance d from the origin A of a coordinate system as shown in the
diagram.
At which of the following points is the electric field least in magnit
1/1
A solid conducting sphere is given a positive charge Q. How is the charge Q distributed in or on
the sphere?
It is concentrated at the center of the sphere. It is uniformly distributed throughout the sphere.
Its density decreases radially outward from
1
1/1
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1/1
Each of five satellites makes a circular orbit about an object that is much more massive than any
of the satellites. The mass and orbital radius of each satellite are given below. Which satellite has
the greatest speed?
mass = m/2; radius
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1
1
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If the mass of a simple pendulum is doubled but its length remains constant, its period is
multiplied by a factor of
1/2 2-1/2
1 21/2 2
2. 1/1 points All Submissions No
1
1
1/1
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1/1
The maximum efficiency of a heat engine that operates between temperatures of 1500 K in the
firing chamber and 600 K in the exhaust chamber is most nearly
33% 40%
60% 67% 100%
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Sub
This problem and the next are about the following situation. Two positive charges of
magnitude q are each a distance d from the origin A of a coordinate system as shown in the
diagram.
At which of the following points is the electric field least in magnit
The electric potential at point P is most nearly
2.5 x 10-8 V 2.5 x 101 V
9.0 x 102 V 1.8 x 103 V 7.5 x 108 V
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1
0/1
1/1
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There is a counterclockwise current I in a circular loo
Question part
Points
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1
0/1
1/1
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0/1
When a mass is attached to a spring, the period of oscillation is approximately 2.0 s. When the
mass attached to the spring is doubled, the period of oscillation is most nearly
0.5 s 1.0 s 1.4 s 2.0 s
2
0/1
A ball of mass m is suspended from two strings of unequal length as shown in the diagram. The
tensions T1 and T2 in the strings must satisfy which of the following relations?
T1 = T2 T1 > T2
T1 < T2 T1 + T2 = mg T1 - T2 = mg
6. 1/1 points All Submissi
Archimedes Buoyancy Challenge: Density of a Penny
Goal: To use Archimedes Principle to find the density of the density of pennies, correct to two
significant figures.
Theory:
Sunken(1)
Fp,1
Floating(2)
Fp,2
W0
W0
Fnet= Fp,2 - W0=0
Fp,2=W0
Pw*g*Vw,2=m0*g
m
L05 Range of a Projectile
Goal:
To predict the range of a horizontally-launched projectile and test the result experimentally.
Theory:
List of Apparatus:
Table about four ft long or longer
Five or six books or comparable substitutes
Glass marble
Piece of
Demos
n
n
n
n
n
n
Tennis racket to throw
Tennis racket and book to flip
Angular acceleration of 1m and 2 m sticks
Unmatched batons to demonstrate moment of inertia
Bicycle wheel to demo angular velocity and acceleration
Race of cylinder, disk, and sphere
Demos
n
n
n
Big scissors and piece of cardboard
Meter stick seesaw with weights
CoM demos
n
n
n
n
pie plate
wine bottle holder
bird balancer
meter stick balance
Seesaws
Section 2.1
Static Torque
n
Torque: Force Lever
n
n
n
n
n
n
Torque disappears if:
n
n
Demos
Banana on string to swing overhead
n Roll of duct tape to make belt
n Two matching small balls
n Coin-and-feather-drop
n
Characterizing Inertia
n
Mass a measure of objects inertia
n The
greater the mass, the harder it is to change an
objects motion.
Demos
n
n
n
n
n
Shoot the monkey
Simultaneous drop demo
Howitzer (ball shot vertically up from rolling cart)
Two matched spring scales (for 2 students to
push/pull on each other)
Block and big wooden board to make a ramp
Falling Balls
Section 1.2
Vectors
Demos
Pendulum hung from ceiling frame
n Force plates
n
Conservation of Energy
1 2
n Mechanical energy = E = KE + PE = mv +mgh
2
n v
= speed (magnitude of velocity)
n h = height above the ground
n
The quantity E is conserved (doesnt change)
n Choose
any
Demos
Two spring scales and skateboard
n Several balls
n
n 2
medicine balls; 2 matched smaller balls
Pendulum hung from ceiling frame
n Ramp and rolling cart to pull with scale
n
Ramps
Section 1.3
This section doesnt have a lot to say
about the ramp per s
Apparatus List
bowling ball and tennis ball
air pucks
banana cutting
Physics 100 How Things Work
Instructor: Stefan A Jeglinski
Office: 174 Phillips
Phone: 919-962-7171
Email: [email protected]
Office Hours: TBA,
& by appointment
Lecture: MWF a
Skating 1
Apparatus List
mystery box with bowling ball
air pucks
tablecloth demo
Office Hours
n
Dr J (Phillips 174)
Tue 9:30-11a
n Thu 1:30-2:30p
n by appt
n
n
Christina Haig
Phillips 365 Fri 2-3p
n SI TBA, see poll announcement
n
Peer Tutoring
for Fall 2
Demos
n
Coin and Paper
Falling Balls
Section 1.2
Clicker Question
n
Suppose I throw a ball upward into the air.
After the ball leaves my hand, is there any
force pushing the ball upward? (ignore drag
due to the presence of air)
A.
Yes
No
B.
Clicker Questi
8.2 A ball of mass m falls from a height h to the floor. S (a) Write the
appropriate version of Equation 8.2 for the system of the ball and the Earth and
use it to calculate the speed of the ball just before it strikes the Earth. (b) Write
the appropriate
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1
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Enter your net force equations:
F_p=T-m*g*sin(A)
F_n=N-m*g*cos(A)
Key:
mg T T +y
mg +xT L20Bint. Interpretations for Simple Harmonic Motion of a Vertical Spring
mg
Part 1: Graphical Analysis
1. The fit coefficient that represents the angular velocity is B.
2. =2 /T
T=2 /
T=2 /9.017 1/s
T=.697 s
The period on the graph was ab
Qualitative:
A possible source of error is timing error. We minimized the timing error by timing ten cycles and dividing the
total time by ten to find the period; however, the starting and stopping times are not always consistent. Another
possible source
L07b
1. Tension of the string is an external force of the system that does no work. The
tension force does no work because it acts in the direction perpendicular to the
motion of the bob. The angle between the force of tension and its direction of
motion
Spark
Index
n
Elapsed Time
tn
(s)
Position
xn
(m)
Change in
Position
xn
(m)
Change in
time
tn
(s)
Average
Velocity
xn/tn
(m/s)
0
0
0
1
.1000
0.0141
.0327
.2000
.1635
2
.2000
0.0327
.0395
.2000
.1975
3
.3000
0.0536
.0458
.2000
.2290
4
.4000
0.0785
.0525
.