Homework #13
Physics 1112
References:
Chap. 18, intro., sections 18.1-5; Chap. 19, all
Physics Ideas:
Math Skills:
Spring 2015
Kinetic Molecular Theory of Ideal Gases
Equipartition of Energy principle
Ideal Gas Properties & Processes
Thermodynamic States,
Phys 1112 Homework #1A Solutions
Textbook Q1.10 [Units & Dimensional Analysis] The units of volume are L3; that is, the units
of length cubed. The equation for the volume of a cylinder cannot be V = r 3 h since the units
of this volume would be L4.
#1. [M
Phys 1112 Homework #14 Solutions
#1. [from Lecture]
Q20.14 [Frictionless Heat Engine]
Even in the total absence of friction, the 2nd Law of Thermodynamics would limit conversion of
disordered thermal energy into ordered work. No engine is 100% efficien
Phys 1112 Homework #5 Solutions
#5.115 [Spindletop]
r
r
Apply F = ma to the person. The person moves in a horizontal circle so his acceleration is
arad = v2/R, directed toward the center of the circle. The target variable is the coefficient of static
fric
Phys 1112 Homework #2 Solutions
#3.9 [Textbook Projectile] The textbook slides of the table, so it has initially only a horizontal
initial velocity and the vertical velocity is zero: v0y = 0 m/s
1
(a) y = y0 + v0 y t gt 2
2
1
1
m
0 = y0 gt 2 y0 = 9.8 2 (
Phys 1112 Homework #8 Solutions
#8.47. When the spring is compressed the maximum amount the two blocks arent moving
relative to each other and have the same velocity V relative to the surface. Apply conservation of
momentum to find V and conservation of e
Phys 1112 Homework #11 Solutions
Q10.30 [Gyroscope]
The precession frequency is proportional to the torque on the gyroscope. So, adding weight at
the end of the gyroscope axis will increase the torque acting on the gyroscope about the pivot,
thereby in
Phys 1112 Homework #9 Solutions
#11.48 [Pickup Truck] The free-body
diagram for the truck is shown below:
FF
FR
d
w
x
xcm
W
FF = 10,780 N, FR = 8820 N, w = 3600 N, x = 1.00 m, d = 3.00 m.
(a) Without the box in the truck, the center of mass (cm) of the
Phys 1112 Homework #13 Solutions
#18.71 [Balloon]
4
p = 1.25atm, T = 22.0 C + 273 = 295K , V = r 3 = 0.065m3 , mmolar = 28.0 g / mol
3
28 10 3 kg / mol
(a) The molar mass is given by mmolar = mN2 N A , so mN2 =
= 4.65 10 26 kg
23
6.023 10
3
(b) The ave
Phys 1112 Homework #3 Solutions
#13.11 [Gravitational force]
The magnitude of the acceleration due to earth at a given distant r away from the center of the earth
GM
is aE (r) = 2
r . Note that this only holds for r larger or equal to the radius of earth
Homework #8
Physics 1112
References:
Chap. 8, intro., sections 8.4-6; Lecture & Reading notes on 1-D Elastic Collisions
Chap. 9, intro., sections 9.1-6 (NOTE: We'll defer a detailed treatment of
rotational KE until next week. For now we'll concentrate jus
Phys 1112 Homework #10 Solutions
#10.42 [Block on Table] m = 0.0250 kg, R = 0.300 m, = 1.75 rad/s
(a) Angular momentum is conserved because the lever arm of the
tension, T, with respect to the axis of rotation is zero and therefore
there is no torque a
Phys 1112 Homework #12 Solutions
Q14.20 [Buildings & Earthquakes] In order to avoid resonance, where small displacements are
greatly amplified, the natural frequency of the structure should be far away from the typical
earthquake frequencies.
Since dam
Phys 1112 Homework #4 Solutions
#Q4.3 [Helium Balloon]
Assuming that there is no string attached to the balloon that holds it in place the two forces that
act on it are the buoyancy force FB and the weight of the helium plus the balloon W=mg. The
buoyancy
Physics 1112
Homework #1B Solutions
#3.83 [Soccer Pass]
N (y)
vb/g = 12.0m / s, vJ /g = 8.00m / s, and = 37
vb/g = vb/J + vJ /g which is the same as vb/J = vb/g vJ /g
Now we take a look at the x and y-components of vb/J
x component: vb/J sin = vb/g sin
E