PHYS 132, WEEK 11 November 29-December 3
19.3. Solve: (a) During each cycle, the heat transferred into the engine is Q H = 55 kJ , and the heat exhausted is Q C = 40 kJ . The thermal
efficiency of the heat engine is
h = 1QC QH = 140 kJ 55 kJ = 0.273
15.1. Solve: The density of the liquid is
=
m 0.120 kg 0.120 kg = = = 1200 kg m 3 V 100 mL 100 10 -3 10 -3 m 3
Assess: The liquid's density is more than that of water (1000 kg/m3) and is a reasonable number.
15.2. Solve: The volume of the helium
Andy Gawne Phys-0133-51 Problem 32.45 Problem: a) What is the magnetic field strength 2 m from a long, straight wire carrying a current of 10 A? b) What percentage of the earth's magnetic field is your answer to (a)? c) High-voltage transmission line
Andy Gawne PHYS 133-51
Problem: The capacitors are charged and the switch closes at t = 0s. At what time has the current in the 8 resistor decayed to half the value it had immediately after the switch was closed? Model: We assume that the wire is i
Andy Gawne PHYS-0133-51 Problem 29.48 Problem: A proton is fired with a speed of 200,000 m/s from the midpoint of the capacitor toward the positive plate. Show that this is insufficient speed to reach the positive plate. What is the proton's speed as
Andy Gawne PHYS-0133-51 Problem 26.45 Problem: A thin rod with length L has a charge of Q. Find an expression for the electric field E at a distance x from the end of the rod. Give your answer in component form. Model:
Visualize: The figure shows th
PHYS 132, WEEK #5, CHAPTER 23
23.7. Model: Light rays travel in straight lines and follow the law of reflection.
Visualize:
Solve:
We are asked to obtain the distance h = x1 + 5.0 cm. From the geometry of the diagram,
tan q i = x1 10 cm tan q r =
PHYS 132, WEEK 4, CHAPTER 22
22.2. Model: Two closely spaced slits produce a double-slit interference pattern.
Visualize: The interference pattern looks like the photograph .of Figure 22.3(b). It is symmetrical, with the m = 2 fringes on both sides
PHYS 132, WEEK 2
20.2. Model: This is a wave traveling at constant speed. The pulse moves 1 m to the left every second.
Visualize: Please refer to Figure Ex20.2. This snapshot graph shows the wave at all points on the x-axis at t = 2 s. You can see
Energy
10:1 ANatural Money" Called Energy
1. One month, John has income of $3000, expenses of $2500, and he sells $300 of stocks.
a. Can you determine Johns liquid assets L at the end of the month? If so, what is L? If not,
Why or? I40 , VJL 60"0idt'l'
PHYS 132, WEEK 9 NOVEMBER 15-18
18.16. Solve: The average translational kinetic energy per molecule is
e avg =
1 2 mv rms =
2
3 2
k B T vrms =
3k B T m
Since we want the vrms for H2 and N2 to be equal,
3k B TH 2 mH2 = 3kB T mN2
TH 2 =
mH2 mN
PHYS 132, WEEK #8 NOV 8-12, 2004
17.4. Model: The work done on a gas is the negative of the area under the pV curve.
Visualize: Please refer to Figure Ex17.4. The gas is expanding, so we expect the work to be negative. Solve: The area under the pV cu
14.4. Model: The air-track glider attached to a spring is in simple harmonic motion.
Visualize: The position of the glider can be represented as x(t) = A cos wt. Solve: The glider is pulled to the right and released from rest at t = 0 s . It then osc
18.1. Solve: We can use the ideal-gas law in the form pV = NkBT to determine the Loschmidt number (N/V):
1.013 10 5 Pa N p = 2.69 10 25 m -3 = = V kB T (1.38 10 -23 J K )(273 K )
(
)
18.2. Solve: Nitrogen is a diatomic molecule, so r 1.0 10-1
17.1. Model: For a gas, the thermal energy is the total kinetic energy of the moving molecules. That is, Eth =
Kmicro. Solve: The number of atoms is
N=
M 0.0020 kg = = 3.01 10 23 m 6.64 10 -27 kg
Because helium atoms have an atomic mass number A
16.1. Solve: The mass of lead mPb = Pb VPb = (11,300 kg m 3 )(2.0 m 3 ) = 22,600 kg . For water to have the
same mass its volume must be
Vwater =
mwater 22,600 kg = = 22.6 m 3 water 1000 kg m 3
16.2. Solve: The volume of the uranium nucleus is
V
14.1. Solve: The frequency generated by a guitar string is 440 Hz. The period is the inverse of the frequency, hence
T= 1 1 = = 2.27 10 -3 s = 2.27 ms f 440 Hz
14.2. Solve: Your pulse or heart beat is 75 beats per minute. The frequency of your hear
13.1. Model: The crankshaft is a rotating rigid body.
Solve: The crankshaft at t = 0 s has an angular velocity of 250 rad/s. It gradually slows down to 50 rad/s in 2 s, maintains a constant angular velocity for 2 s until t = 4 s, and then speeds up
12.1.
Solve: (b)
Model: Model the sun (s), the earth (e), and the moon (m) as spherical. (a)
Fs on e =
Gms me (6.67 10 -11 N m 2 / kg 2 )(1.99 10 30 kg)(5.98 10 24 kg) = 3.53 10 22 N = (1.50 1011 m ) 2 rs2 e -
Fm on e =
GMm Me (6.67 10 -1
11.1. Visualize:r Please refer to Figure Ex11.1. r
Solve: (b) (c)
(a) A B = AB cos = ( 4)(5)cos 40 = 15.3. r r C D = CD cos = (2)( 4)cos120 = -4.0. r r E F = EF cos = (3)( 4)cos 90 = 0.
11.2. Visualize:r Please refer to Figure Ex11.2. r
Solve