|
PHYSICS HOMEWORK
Here are some
of the answers to the homework.
The idea is to do the problem then check your answer. If you get it incorrect;
go back and attempt to find the mistake. It is better for your understanding
if you can find your own mistakes and learn from them.
----update 12/19/22 ----
-------------------------------------------------------------------------------------------------------------------------------------
Chapter 1
Page 15, 27
Page 15
#1) 5x10-5 m
#2) 1x10-6 seconds
#3a) 1x10-8 m
#3b) 1.0x10-5 mm
#3c) 1x10-2 µm
Page 27
#6) m2 / s2
#7) kg / s
#9) size of unit is standard and reproducible
#10) kg • m2 / s2
Page 20, 28
Page 20
#3) a) .67 b) 14 c) 778.92 d) 797.5
Page 28
#16) a) 1 b) 3 c) 5 d) 4 e) 4 f) 6
#18) a) 3.00x108m/s b) 2.9979x108m/s c) 2.997925x108m/s
#19) a) 3 b) 4 c) 3 d) 2
#20) a) 797g b) .90m/s c) 17.8mm d) 23.7s
#22) 115.9m
Page 25, 33
Page 25
#4) graph A
#5) C (because masss divided by volume equals 1.29)
Page 33
#11) C
#12) F
Page 29, 31
Page 29
#24) this is a little bit opinionated so if you are a little off from
me it is OK a) 10-2m b) 100m c) 101m
d) 101m e) 102m
#27) This question is asking you to see if the units on the right side
will cancel to equal the units on the left side
#35) ahhhhhhh, about 700
#36) about 1x105 balls
Page 31
#45a) .619 g/cm3
#45b) 4.57x1016m2
--------------------------------------------------------------------------
Chapter 2
Page 44, 47, 68
Page 44
#4) 3.00h
#6a) 6.4 h
#6b) 77 km/h south
Page 47
#3a) 2.50m/s to south
#3b) 2.27m/s to north
#3c) 0 m/s
Page 68
#7) 10.1 km to east
#8) 4.22x104 m
#9a) +70.0m
#9b) +140.0m
#9c) +14m/s
#9d) +28m/s
Worksheet Velocity Graphing
#1a) about 2.5 m/s
#1b) 0 m/s
#1c) about -3.75 m/s
#1d) about 1.25 m/s
#4) A-B increasing velocity
B-C constant velocity
C-D constant velocity (less than B-C)
D-E zero velocity
E-F constant negative velocity
F-G constant negative velocity (more than E-F)
G-H constant negative velocity (less than F-G)
#6a) about 2.3 m/s
#6b) about .67 m/s
#6c) about 1.25 m/s
Page 49, 59, 69
Page 49
#1) 2.2 s
#4) -3.5x10(-3) m/s(2)
#5a) 1.4 m/s (it is asking for the change in velocity)
#5b) 3.1 m/s (this is the toughest question of this homework)
Page 59
#5a) 0-30s, 60-125s, 210-275s
#5b) all straight lines
#5c) skip
#5d) skip
#5e) 0-30s, 210-275s
#5f) same as #5a
#5g) + slope = + acceleration and - slope = - acceleration
#6) No, + direction 30-210s, and - direction 275-600s
Page 69
#17) 0 m/s(2), 1.3 m/s(2), .65 m/s(2)
Worksheet Acceleration
#1) 1700 m
#2) 1.2 s
#3) 71 m/s
#4a) 24 s
#4b) 740 m
#5a) 3.1x10(8) m/s(2)
#5b) 1.1x10(-5) s
#6a) -20. m/s
#6b) -20. m
--------------------------------------------------------------------------
Chapter 3
Page 85, 108
Page 85
#1) a)v b)s c)s d)v e)s
#2) about 125m at about 10°
#5) zero meters
Page 108
#2) No, even if oposite there will be a resultant
#10) same exact direction
Page 89, 92, 94(practice C)
Page 89
#2) 46m and 81°
Page 92
#1) 95.2 km/h
#2) 44.4 km/h
#3) 21 m/s (vx) and 5.7 m/s (vy)
#4) horizontal is 0m and verticlal is 5m
Page 94
#2) 7.6km and 26°
#3) 13m and 57°
Page 109, 105(practice F)
Page 109
#24) 108.3m (x) and -19.1m (y)
#25) 1.31km North (y axis) and 2.81km East (x axis)
#26) 240.0m and 237.2°
#41a) 70m/s east
#41b) 20m/s
Page 105
#2) 14.5m/s (in the direction aircraft carrier is moving)
Page 99, 101(practice E), 109
Page 99
#2) 4.9 m/s
#3) 7.6 m/s
#4) 5.6m
Page 101
#1) y = -2.3m so he is OK and will make it to the other roof
#3) t = 2.0s and ymax = 4.8m
Projectile Worksheet
#1) (time is 5.5s) answer is 44m from the cliff
#2) 7.3m from the base (x direction) and -33m or +33m high (y direction)
#3a) 5.1s
#3b) (214.2m) answer with correct sig. figs. is 210m
#4) 31m/s (this is a tough problem because you will have two unknowns
in the equation)
Steps I used are as follows:
1. I broke the "unknown" vector into its components (you don't
get a number, just a trig. equation for each component)
2. I used the swiss army equation twice, one in y direction and the other
in x direction (at this point each equation has two unknowns, but we are
OK because they are the exact same unknowns, Vi and t.
3. I then did algebra with the x direction swiss army for t
4. I then substituted it into the y direction swiss army as t (leaving
only one unkown, Vi, which is the answer to the question)
#5) 78m
#6) (time is 4.0s) answer is 92m away from the cannon
--------------------------------------------------------------------------
Chapter 4
Force Worksheet
#1) 490. N
#2) 83 kg
#3a) 0N
#3b) 13N
#3c) 730N
#6) weight is -625N and mass is 63.8kg
#7) Fg is 592N so NO, Tarzan will break the vine
#8) 57N
#9) .12
#10) acceleration (chute still closed) is 9.80m/s(2) and net force on
skydiver (chute open) is 142N
#11) .83 m/s(2)
#12a) 2.0x10(7)N
#12b) 5.0 m/s(2)
#13) 1.3 m/s(2) down
CD 5-1 & 5-2, Page 124(Practice A), 129, 132, 134, 139, 145
CD 5-1 page 17
#3a) equal to
#3b) zero
#3c) equal to
#5) 150N
#7) 250N
#8) 0m/s2, 1m/s2, 5m/s2
CD 5-1 page 18
a) +10m/s2 b) +6m/s2 c) 0 d) -2m/s2 e) -10m/s2 f) 0
CD5-2 page 19
#1a) 4m/s2, 8m/s2, 250N
#1b) 2m/s2, 6m/s2
Page 129
#1) zero
#2) -3674N
Page 132
#1) 2.2 m/s(2) forward
#5) 14N
Page 139
#2a) .67
#2b) .52
Page 128, 147
Page 128
#1) x = 60.6N and y = 35.0N
#3) 557N and 125.7°
Page 147
#29) 51N
#26a) 54N
#26b) 53N
#26c) 49N
#26d) 38N
Inclined Plane Worksheet
#1) 4.6 m/s(2) down the plane
#2) 7106 N
#3) 2.05 m/s(2) down the hill
#4) 2106 N up the hill
--------------------------------------------------------------------------
Chapter 5
WORK - sheet
#3) 365 J
#4) -274 J
#5) zero
#6) 779 J
#7) 1150 Watts and 1.15 kW
#8) 1.3x10(5) N
#9) 59.9 kg
#10) 7.7 J
#11a) 5.5x10(3) J
#11b) None
#11c) -5.5x10(3) J
#11d) No
#11e) 2200 Watts
#12) 160 Watts
#13) 54.7 m
nRg Worksheet
#1) 1.1x10(5) J
#2) 1.7x10(4) J and 6.8x10(4) J
#3) 9.5 m/s
#4) 85 J
#5) 1.9x10(4) J
#6) 75 m
#7) 11 m
#8) 7.3 m
#9) 1180 J
#10a) 5.0x10(3) J
#10b) 5.0x10(3) J
#10c) 5.0x10(3) J
Page 168, 184
Page 168
#1) 7.8 m
#2) 21 m
#4) 3.0x10(2) N
Page 184
#7) 53 J by person and -53 J by gravity
#19) 7.6x10(4) J
#36) 5.9x10(8) W
--------------------------------------------------------------------------
Chapter 6
MO' Problems Worksheet
#1) 3100 kg•m/s
#2) 53,000 kg•m/s
#3) 1.4x10(8) kg•m/s
#4) 11 kg•m/s
#5) 6200 N (in opposite direction)
#6) 1.8 m/s
#7) -59 m/s
#8) -.073 m/s
#9) -7.91 m/s
#13) 14 m/s
More MO' Problems Worksheet
#1a) 4.0 m/s
#1b) 800 J
#1c) 8.0 J
#1d) 792 J
#2a) Inelastic
#2b) Inelastic
#2c) Elastic
#2d) Elastic
#2e) Inelastic
#4) 380 N to the left
#5) 16 kg•m/s to the south
#6) 9.0 m/s to the right
#7) zero (because velocity is zero)
--------------------------------------------------------------------------
Chapter 7
Page 236, 238, 239
Page 236
#1) 2.5 m/s
#3) 1.5 m/s(2)
Page 238
#1) 29.6 kg
#3) 40.0 N
WS Kepler and Newton
#4) .0615 days
#5) 4.30x10(4) km
#9) 6.5x10(-8) N (*Hint: if you got 6.5x10(-12) you need to check your
units)
#10a) 491 N
#10b) 490. N (*Hint: you will use the old equation for Force)
#11) one ball is .37 kg and other is .74 kg (*Hint: let one of the balls
be "x" and the other be "2x")
WS Satellites
#2a) 2.85x10(3) m/s
#2b) 5970 seconds and 1.66 hours
#3) 2.96x10(4) m/s
#4a) 1.0x10(41) kg
#4b) 5.0x10(10) stars in our galaxy
#4c) 1.7x10(5) m/s
WS Gravitation
#1) 12 earth years
#2) .0915 days
#3) 7.90x10(3) seconds
#4) 5.96x10(24) kg
#5) 2.4x10(-6) N
#7) 3070 m/s
--------------------------------------------------------------------------
Chapter 7+ and 8
Page 258, 261, 266, 288
Page 258
#1) .75 N•m
#2a) 5.1 N•m
#2b) 15 N•m
#3) 133 N
Page 261
#6) 2.7
Page 266
#47) 72 %
WS Simple Machines / Fluids
#1a)wheel & axel b)lever c)wedge d)lever e)lever and also wheel &
axel
#2a) 4.0
#2b) 1.9
#2c) 48%
#3a) 1.74
#3b) 87.2%
#4a) increase
#4b) same
#5a) large
#5b) small
#5c) small
#6.1) 1
#6.2) 2
#6.3) 2
#7) pressure at top also increases
#8) No ('cuz no weight)
#9) water pressure goes down ('cuz Bernoulli's Principle)
#10) pressure increases ('cuz same force is now applied to smaller area)
#11) pitcher ('cuz amount of total water is not important, but depth is)
#12) 5.0 N
--------------------------------------------------------------------------
Chapter 9 and 10
WS Heat
#5) 1390 J
#6) 1.0 x 10(6) J
#other6) 1.00x10(3) J/kg°C
#9) 171 J/kg°C
#10) 63°C
#12) 12.7°C
WS Latent Heat
#10) Yes, a change of state
#11) released
#13) 37300 J
#14) 502,000 J
#15) 941,000 J
#16a) 36°C
#16b) 62°C
WS Thermodynamics
#14) scrambled egg
#17) 4400 g
#22) 35.6°C
#1a) iceberg
#1b) hot tea
--------------------------------------------------------------------------
Final Exam Practice
1) 100 fold less
2) t=.84s
3) -2m/s2
4) 34N
5) Upward
6) 15.3 N
7) 176m
8) 6.5m 67° N of E
9) 8.8x10(6)J
10) 76.7°C
11) 3.38x10(-6)N
12) no question
13) 14,700N
14) 2.82x10(5)N
15) 294J
16) 95m/s, 55m/s
17) 2.9x10(2)
18) 17m/s
19) 224m
20) 80km/h
21) 13blocks
22) 5.7m/s
23) 225m
24) 176m
25) 3rd
26) 26470W
27) -.6m/s
28) 7.6m/s
29) 20N
30) no question
31) 10N
32) 6450m/s
33) 4.16m/s
34) 28m/s
35) Equal to
36) 290
37) 0
38) 9.8 N
39) 200m
40) 111m
41) 7.2m
42) 1.11km
43) no question
44) no question
45) 2500W
46) 128
47) 1.8Ns
48) 108J
49) 17m/s
50) 30m/s
51) 4
52) no question
53) 4.2m/s
54) 76.3m
55) 3.7x10(6)J
56) 5.7m/s
57) 28m/s
58) 27
59) Gravity
60) 6.33°C
61) 2700km
62) no question
63) no question
64) A
65) 3m/s2 down
66) 3.5m
67) Into reordering the molecules (changing phase)
68) 7.25x10(-7)m
69) Numbers come from measurements
70) 5.3m/s2
71) 5.6m/s2
72) .20
--------------------------------------------------------------------------------------------------------------------------------------
SECOND SEMESTER
Chapter 16a
WS - Static Electricity
#2) Some insulators: dry air, wood, plastic, glass, cloth, pure water
Some conductors: metals, tap water, human body
#5) 7.3x10(-18) N
#6) 3.0x10(-6) C (its also positive but that wasn't asked)
#7) .70 m
#8) 1.6x10(-3) C
#9) 9.2x10(-26) N south
#10) 2.0x10(14) e- too many
#11a) 5.2x10(22) atoms
#11b) 1.5x10(24) e-
#11c) -2.4x10(5) C
#11d) balanced by equal number of p+
--------------------------------------------------------------------------
Chapter 16b
WS - Electric Field
#3) 72 Joules
#4) 2.9x10(-19) Joules
#5) 2.3x10(9) Volts
#6) 25,000 N/C
#7 second part) 1.6x10(9) V
#8) 3.6x10(-5) C
#10a) 3.2x10(-19) C
#10b) 2 e-
#11) 4.7x10(10) N/C
--------------------------------------------------------------------------
Chapter 17
Page 609, 623, 627
Page 609 #1) 400. s
#4) 20. C
#5a) .0026 A
#5b) 1.6x10(17) e-
#5c) .0052 A
Page 623 #3) 1.4x10(-5) W
#4) $0.13
Current Electricity WS
#3a) 1.5 A
#3b) No
#4a) 240 Ω
#4b) 60. W
#5) 4.0 A
#6) 45 V
#8a)12.0 A
#8b) 1440 W
#8c) 14400 J
--------------------------------------------------------------------------
Chapter 18
SERIES WS
#1a) 60 Ω
#1b) 2 A
#2a) 30 Ω
#2b) 3 A
#3a) increase
#3b) decrease
#3c) no
#4a) 2000 Ω
#4b) 200 Ω
#5a) 50.0 Ω
#5b) 2.4 A
#5c) v1drop= 48V v2drop= 72V
#5d) 120 V
#6a) 1.20x10(4) Ω
#6b) 0.0010 A
#6c) v1drop= 3.0V v2drop= 5.0V v3drop= 4.0V
#6d) 12 V
#7) 15 V
PARALLEL WS
#1a) 5.0 Ω
#1b) 6 A
#1c) 2 A
#2a) 6.67 Ω
#2b) 2.25 A
#2c) I1=1.25A I2=1.00A
#3a) 20.0 Ω
#3b) .600 A
#3c) I1=0.100A I2=0.200A I3=0.300A
#4a) smaller
#4b) larger
#4c) no
WS 35-1
series side
#1) 3
#2) 6
#3) 12
#4) Through , Across
#5) Simultaneously
#6a)B b)A c)4&6 d)5 e)4&6 f)B g)B
parallel side
#1a) 3
#1b) 6
#1c) all are 3 except the bottom two are 6
#2a) d should be crossed out
#3a) 6
#3b) 3, 3, 6
#3b the next one) 12
#3c) 0.5
COMBINED WS
#1b) 30 Ω
#1c) 60 Ω
#1d) 2 A
#1e) 60 V
#1f) 60 V
#1g) 1 A
#2b) 5 Ω
#2c) 15 Ω
#2d) 3 A
#2e) 30 V
#7a)S b)S c)P d)S e)P f)S g)S h)P i)P
WS page 132
#4b)
2A, 2V, 4W
2A, 4V, 8W
#4c)
1A, 6V, 6W
2A, 6V, 12W
#4d)
1.5A, 3V, 4.5W
1.5A, 3V, 4.5W
3A, 3V, 9W
Practice Test ch16-18
#1) electron
#2) repulsive
#3) the charged person induces a charge in the ball
#4) stationary
#5) 3.0x10(14) too many
#7) 9.2x10(5) N/C
#8) 2.8 V
#9) 5.9x10(5) N attraction
#10 23 ohms
#11) 5.2 ohms
--------------------------------------------------------------------------
Chapter 19
B WS - Theory
#4) domains
#5) field
#6) force , perpendicular
#8a) North
#8b) West
13) (if we assume student perspctive in a classroom) it will be Right
to Left
B WS - Calculations
#1) 5.4x10(-11) N
#2) 2.6 T
#3) 7.4x10(-5) T
#4) 1.34 A
#5) 7.7x10(-14) N
#6) 9.0x10(4) m
#7) 1.6x10(-3) N
--------------------------------------------------------------------------
Chapter 20
WS - Transformers
#3a) 781 turns
#3b) 44 turns
#3c) 7.5 turns
#4a) 1800 V
#4b) 30. A
#4c) Power in = 3600 W and Power out = 3600 W
WS - Transmitting Power
#1a) 36 turns
#1b) .0095 A
#2a) 1 to 200
#2b) 0.200 A
#3b) 2 to 1
#3c) 5 A
--------------------------------------------------------------------------
Chapter 11
WS - SHM
#1) 0.248 m
#2) 3.3 m/s2
#5a) 1.6 s
#5b) 2.7 m
#5c) because square root of L
#5d) No
#6) 210 N/m or kg/s2
WS - Wave Homework
#1) 0.0105m, 3310Hz, 0.000302s
#2) inversely
#3) 0.25s
#4) 4Hz
#5) 50.m/s
#9) 330m/s
#10) 0.00382s
WS - Superposition
#1a) partially reflected, partially transmitted
#1b) erect
#1c) almost totally reflected
#1d) inverted
#3) frequency
#5) no change
#8) inverted
#9) erect
--------------------------------------------------------------------------
Chapter 12
WS - Sound
#3) 228 m
#4) 1500 m
#5) 1800 m/s
#7) open pipe = 10.5m and closed pipe = 5.23m
#8) 368 Hz or 372 Hz
#14) increase f, decrease wavelength, velocity and amplitude are same
WS - Name that Sound
#1)E #2)B #3)C #4) F #5)D #6)A
WS - CD 26-1
#3) about 2.5 cm
#5b) 9 seconds
#12) I used 25°C so answer is 347 m/s
--------------------------------------------------------------------------
Chapter 13
WS - Light
#15) 7.00x10(-7) m
#16) 3.84x10(8) m
#17) 5.0x10(2) s
#18) 2.0 lx
#19) 8.0x10(3) lm
--------------------------------------------------------------------------
Chapter 13b & 14
WS - Reflection & Refraction
#3) crown glass, because it has a lower index of refraction
#7) The ray is totally relfected and none is refracted
#10) angle of regraction will decrease as index of refraction increases
#11a) 53°
#11b) 106°
#12a) 1.33
#12b) water
#13) 21.0°
#14) 1.24x10(8) m/s
#15) 24.4°
#17a) 19.2°
#17b) 30.0°
#17c) away
#17d) parallel but in a different location
--------------------------------------------------------------------------
Chapter 13c & 14b
WS - Mirror / Lens
#1a) -8.0cm
#1c) 6.0cm
#1d) virtual, erect, larger
#2a) -2.7cm
#2c) 2.0cm
#2d) virtual, erect, smaller
#3a) 15cm
#3c) -4.5cm
#3d) real, inverted, larger
#5) 25cm
#6) -37.5cm and virtual, erect, smaller
--------------------------------------------------------------------------
Final Exam Review
1) 0.17 Hz
2) 0.833 A
3) ammeter
4) refraction
5) 22.5 ohm
6) 90. ohm
7) 28°
8) reflection
9) compressions and rarefactions that travel parallel to the wave
10) antinodes that travel perpendicular to the wave
11) RGB
12) reflection or refraction
13) amount of energy (like volume of sound)
14) frequency (pitch)
15) 0.0043 A
16) ohm's law
17) insulator does not conduct electricity
18) 5 , 1
19) flow of light from a source
20) ammeter
21) 9.0x10(3) N
22) upside down y looking thing (greek lambda)
23) watts
24) greek omega
25) pascals (N/m3)
26) 17 ohm
27) 3.0 A
28) node
29) 87.5 Hz
30) 0.756 m
31) 30.9°
32) 111 Hz
33) concentric circles (1st R-hand rule)
34) lights hits boundary of two media at or beyond the critical angel
35) inverted
36) 60 cm
37) Real, larger, inverted
38) can only see it with our eyes (can't project it)
39) absence of medium
40) conduction (transfer of charge by touching) , induction (transfer
of charge w/o touching)
41) 7.5x10(15) too many
42) it is stuck in one place
43) 4.8x10(-19) C
44) flow of electricity (e-) because of coil of wire moving in B-field
45) 4 Hz and 0.25 s
46) vibration of an object from a matching frequency
47) light is it's own medium (alternating E & B fields)
back to main page
|
