Quizzes from Scott Pratt’s Lectures 1. The average velocity is greatest:

Quizzes from Scott Pratt’s Lectures
1. The average velocity
is greatest:
a) between A and B
b) between B and C
c) between A and C
v02
a) D 
g
A football is thrown with b) D  g 2 v
0
a velocity v0 at an angle of
45 degrees above the
g
1
cos 2
horizontal. Which of the c ) D  g
2
v
0

expressions for the
distance of the throw, D, d ) all of the above
is correct?
sin( 45 )  cos( 45 )  1 / 2
o
o



e) not enough informatio n
2) Which statements are correct?
Assume the objects are static.
A)
B)
C)
D)
T1 must = T2
T2 must = T3
T1 must be < Mg
T1+T2 must be > Mg
a)
b)
c)
d)
e)
A only
A and B only
A, B and C only
All statements
None of the statements
cos(10o)=0.985
sin(10o)=0.173
1. What is your section number?
2. A wheel of radius 7 m rotates at 300 rpm.
What is the linear speed of a point on the rim?
a)
b)
c)
d)
e)
140p m/s
35/p m/s
70p m/s
300/p m/s
600p m/s
1. What is your section number?
2. What is TR, the tension in the
right-side cable?
Given: Mg = 2400 N
a) 400 N
b) 600 N
c) 800 N
d) 1200 N
e) 3000 N
a
1. What is your section number?
2. In order of largest to smallest,
list the objects according to
their moment of inertia. All
three objects have the same
mass M which is uniformly
distributed in the plane
according to the green color.
a)
b)
c)
d)
e)
Cylinder, big block, little block
Little block, big block, cylinder
Big block, little block, cylinder
Big block, cylinder, little block
None of the above
cylinder
block
2a
a
block
1. What is your section number?
2. How many calories are required to heat one liter of
water from 20 ºC to 30 ºC?
a)
b)
c)
d)
e)
10, 000
20,000
23.45
50,000
320,000
1. What is your section number?
2. In an effort to reduce heating costs in his
bunker, Dictator Dan doubles the thickness of his
concrete walls. Which of the following is true?
a) The conductivity gets doubled
b) The conductivity is halved
c) The R-value is doubled
d) The R-value is halved
e) None of the above
1. What is your section #?
2. A massive copper piston traps an ideal
gas as shown to the right. The piston is
allowed to freely slide up and down and
equilibrate with the outside air. Pick the
most correct statement?
A. The pressure is higher inside the
cylinder than outside.
B. The temperature inside the cylinder
is higher than outside the cylinder.
C. If the gas is heated by applying a
flame to cylinder, and the piston comes to a new
equilibrium, the inside pressure will have increased.
D. All of the above.
E. A and C.
Outside Air: Room T, Atm. P
1. What is your section #?
2. A massive piston traps an amount of
Helium gas as shown. The piston freely
slides up and down.
The system initially equilibrates at
room temperature, T = Ta = 20 ºC (a)
The gas is then slowly heated
until T = Tb = 100 ºC (b)
A. Pa = Pb
B. Wab > 0
C. Qab > Wab
D. All of the above.
E. A and C.
Vocabulary: Wab is work done by gas between a and b
Qab is heat added to gas between a and b
1. What is your section #?
2. You are designing an ideal Carnot engine which will
exhaust heat near room temperature at T = 27 ºC. If you
want the engine to be 75% efficient, what is the minimum
temperature of the heat reservoir?
A. 27 ºC
B. 127 ºC
C. 327 ºC
D. 627 ºC
E. 927 ºC
engines :
Tcold
e  1
Thot
refrigerat or :
1
e
Thot / Tcold  1
heat pump :
DATA: 0 ºC = 273 ºK
e
1
1  Tcold / Thot