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Honors Physics Final Exam Key Terms & Concepts List
2009-2010
You should be familiar with the following terms & key concepts discussed in the course:
1. displacement-time, velocity-time, and acceleration-time graphs
2. independent vs. dependent variables
3. distance vs. displacement
4. average speed
5. average vs. instantaneous velocity
6. average vs. instantaneous acceleration
7. acceleration due to gravity
8. scalar vs. vector
9. component
10. resultant
11. projectile
12. trajectory
13. force
14. Newton’s 1st, 2nd, & 3rd Laws of Motion
15. static vs. sliding (kinetic) friction
16. equilibrium
17. normal force
18. tension
19. kinetic energy
20. work
21. Work-Kinetic Energy Theorem
22. power (mechanical)
23. gravitational potential energy
24. elastic potential energy
25. Law of Conservation of Energy
26. impulse
27. momentum
28. Law of Conservation of Momentum
29. differences between elastic, inelastic, & perfectly inelastic collisions
30. angular speed
31. tangential speed
32. centripetal acceleration
33. angular acceleration
34. tangential acceleration
35. centripetal force
36. tangential force
37. torque
38. moment of inertia
39. angular momentum
40. Law of Conservation of Angular Momentum
41. Newton’s Law of Universal Gravitation
42. variation of gravity with distance from the center of a body
43. simple machines
2
44. buoyant force
45. heat
46. temperature
47. conduction, convection, & radiation
48. thermal equilibrium
49. specific heat
50. latent heats of fusion & vaporization
51. entropy
52. relationship between force, acceleration, & velocity for simple harmonic motion
53. period of a pendulum & a mass on a spring
54. transverse vs. longitudinal waves
55. mechanical vs. electromagnetic waves
56. speed, period, wavelength, & frequency of a wave
57. reflection
58. refraction
59. diffraction
60. constructive vs. destructive vs. complete destructive interference
61. resonance
62. Doppler effect
63. relationship between sound intensity and distance from the source
64. relationship between decibel level and perceived loudness of sound
65. relationship between fundamental frequency & harmonic series for an open pipe resonator
66. relationship between fundamental frequency & harmonic series for a closed pipe resonator
67. Snell’s Law
68. critical angle & total internal reflection
69. relationship between illumination & distance from a light source
70. similarities & differences between images produced by plane (flat), concave, & convex mirrors
71. real vs. virtual images
72. magnification
73. differences between a conductor, insulator, semiconductor, & superconductor
74. electrostatic force
75. Coulomb’s Law
76. electric field
77. potential difference
78. capacitor
79. capacitance
80. current
81. voltage
82. resistance
83. power (electrical)
84. relationships for series & parallel resistor arrangements
85. Ohm’s Law
86. kilowatt-hour
87. direction of the force on a charge & current-carrying wire in a magnetic field
88. Faraday’s Law
89. direction of induced current as given by Lenz’s Law
90. function of an electric motors, electric generators, & transformers
3
Honors Physics Final Exam Review Problems
2009-2010
1. A car moving eastward along a straight, level road increases its velocity uniformly from
+16 m/s to +32 m/s in 10 s.
(a) What is its average acceleration?
(b) How far did the car travel while it was accelerating?
(c) If the car were to continue at this rate of acceleration, has fast would it be moving at the end
of 20 s?
2. A motorboat heads due east at 12 m/s across a river that flows due south at a speed of 3.5 m/s.
(a) What is the resultant velocity (magnitude and direction) of the boat?
(b) If the river has a width of 50 m, how long does it take for the boat to cross it?
3. A missile is fired from the ground with an initial speed of 1700 m/s at an initial angle of 55o
relative to the horizontal. Neglecting air resistance, find
(a) the total “hang time” of the missile.
(b) the horizontal range of the missile.
(c) the maximum height of the missile during its trip through the air.
4. A 25 kg suitcase is at rest on the floor of an airport. The coefficient of static friction between
the bottom of the suitcase and the floor is 0.55 while the coefficient of sliding (kinetic) friction
between these same surfaces is 0.30.
(a) What minimum horizontal applied force is necessary to set the suitcase into motion?
(b) Once in motion, if a horizontal force of 200 N is applied to the suitcase, calculate its rate of
acceleration.
(c) If the 200 N force described in part (b) is instead applied at a 30o angle with the ground, find
the rate of acceleration of the suitcase.
5. Over the summer, Megan was spotted pulling her little brother around Shank Park in a shiny red
wagon. If a force of 75 N was used to pull the wagon while the wagon handle was held at an
angle of 50o with the ground, calculate the work done by Megan in pulling the wagon along a
150 m straight path through the park. Also, if it took her 25 s to complete the task, determine
Megan’s power.
6. A 1 kg box is pushed against a relaxed spring (k = 2000 N/m), compressing the spring a distance
of 0.25 m before releasing the box from rest. The box then slides up a frictionless ramp and
onto a rough, elevated surface located a vertical distance of 1.25 m above the release point. If
the coefficient of friction between the bottom of the box and the elevated surface is 0.65,
(a) how fast will the box be moving at the top of the ramp?
(b) how far across the elevated surface will the box travel before coming to rest?
Not Frictionless
k = 2000 N/m
1 kg
Frictionless Ramp
1.25 m
4
7. After being struck by a bowling ball, a 1.5 kg bowling pin moving to the right at 3.0 m/s
collides head-on with another 1.5 kg bowling pin initially at rest. Find the velocity (magnitude
and direction) of the second pin after the collision if the first pin continues to the right, but now
at 0.5 m/s.
8. Mike whirls his new 0.5 kg yo-yo around in a horizontal circle to study centripetal motion. If
the string is 0.8 m long and the yo-yo makes 3 revolutions every second, determine the
frequency, angular frequency, period, tangential speed, and centripetal acceleration of the yo-yo,
as well as the tension (force) in the attached string.
9. A fan blade starts from rest and angularly accelerates at a rate of 2 rad/s2.
(a) How fast is the fan blade turning after 10 s?
(b) Through what angle does the fan blade travel during this time?
(c) How many revolutions does the fan make during this time?
10. A 10 m long metal bar with a mass of 1 kg is pivoted about its center by a pair of forces, as
shown.
F1 = 5 N
F2 = 8 N
30o
r1 = 4 m
r2 = 3 m
40o
(a) Determine the magnitude of the net torque on the bar about the pivot point.
(b) Calculate the rotational inertia of the bar by treating it like a long, thin rod (I =
(c) Find the resulting angular acceleration of the bar.
1
12
mL2).
11. A cylindrical merry-go-round has a mass of 100 kg, a radius of 4.0 m, and rotates at a rate of
0.70 rad/s when a 25 kg boy stands 3.0 m from its center.
(a) If the boy then decides to walk to the center of the merry-go-round, determine its new
angular speed.
(b) Find the initial and final rotational kinetic energies of the system.
12. How much energy is required to change 2 kg of ice at –10oC into water at 25oC?
13. A 5 kg mass is suspended from a vertical spring, causing it to stretch 10 cm.
(a) Calculate the spring constant of the spring.
(b) If the mass is pulled down an additional 10 cm and then released, calculate the period of
oscillation for the mass-spring system.
(c) Find the length of a simple pendulum that would have this same period.
14. A submarine emits a sound directed toward the bottom of the ocean 450 m below. How long
after emitting the sound, will the submarine detect an echo? (Note that the speed of sound in sea
water is 1530 m/s.)
15. Green light has a known wavelength of 5.2 x 10–7 m and travels through the air with a speed of
3 x 108 m/s. Calculate the frequency and period of green light waves.
5
16. A beam of light travels from flint glass (n = 1.61) into water (n = 1.33) with an angle of
incidence of 28.7o.
(a) What is the angle of refraction for the beam?
(b) Determine the critical angle for light traveling from flint glass into water.
(c) Find the speed of light in both the flint glass and the water.
17. For each of the following object locations, calculate the image distance and magnification.
Also, state whether the image is real or virtual, upright or inverted, and smaller, larger, or the
same size as the object. If no image is produced, write “no image.”
(a) An object is placed 20 cm from a concave mirror with a radius of curvature of 25 cm.
(b) An object is placed 20 cm from a convex mirror with a radius of curvature of 25 cm.
(c) An object is placed 10 cm from a concave lens with a focal length of 5 cm.
(d) An object is placed 10 cm from a convex lens with a focal length of 5 cm.
18. A 2 kg particle containing two fewer electrons on its surface than protons is positioned 70 cm
from a 3 kg particle containing a surplus of four electrons.
(a) Determine the gravitational force between the two particles. Is this force attractive or
repulsive?
(b) What is the electrostatic force between these two particles? Is this force attractive or
repulsive?
19. Two point charges are located on the x and y-axes, respectively, as shown below.
(a) What is the magnitude and direction of the electric field at the origin (point P)?
(b) What force (magnitude and direction) would act on a +1 pC charge placed at point P?
(c) Calculate the potential difference between point P and infinity.
q2 = +1 nC
+
q1 = –2 nC
4 cm
–
P
6 cm
20. An initially uncharged, parallel-plate capacitor with a capacitance of 1000 F is charged by
connecting it to a 9 V battery.
(a) When the capacitor is fully charged, how much charge is stored on each plate?
(b) How much electric potential energy is stored in the electric field between its plates?
21. The current in a microwave oven is 6.25 A and the resistance of its circuitry is 17.6 .
(a) Determine the potential difference across the microwave.
(b) Find the power rating of the microwave.
(c) At $0.10/kWh, what is the cost of operating the microwave for 1 hour per day for 30 straight
days?
6
22. Determine the current passing through, voltage drop across, and power consumed by each
resistor in the circuit shown below.
30 
10 20 

15 


6V
23. A magnetic field with a magnitude of 0.5 T acts vertically downward. Determine the magnitude
and direction of the magnetic force acting on each of the following objects:
(a) a 50 mC charge moving eastward at 2500 m/s through the field
(b) a 2 m long wire lying in the field and carrying a 10 A current to the north
24. The loop of wire below has a radius of 30 cm and is placed in a magnetic field acting into the
page, as shown.
(a) If the field is steadily decreased from 0.75 T to 0.25 T over a period of 0.05 s, what emf is
induced in the loop?
(b) If the resistance of the loop is 3 , what is the magnitude of the induced current?
(c) What is the direction of the induced current?
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
7
Honors Physics Final Exam Review Problem Solutions
2009-2010
1.
2.
3.
(b)
(c)
v 32 m/s  16 m/s

= 1.6 m/s2
t
10 s
d = ½ (vf + vi)t = ½ (32 + 16 m/s)(10 s) = 240 m
vf = vi + at = (16 m/s) + (1.6 m/s2)(20 s) = 48 m/s
(a)
R=
(b)
Ry 
 3.5 
  tan 1 
at   tan 1 
 = –16.3o  360o – 16.3o = 343.7o

 12 
Rx 
Time to get cross is independent of river’s speed:
d
50 m
v 
 4.17 s
t 12 m/s
(a)
(a)
(b)
(c)
a avg 
R x 2  R y 2  (12 m/s ) 2  (3.5 m/s) 2 = 12.5 m/s
x-direction
vix = 1700 cos 55o = 975.1 m/s
y-direction
viy = 1700 sin 55o = 1392.6 m/s
a = –9.8 m/s2, vfy = 0 (top)
vfy = viy + at
v fy  v iy 0  1392.6 m/s
t up 

 142 s
a
 9.8 m/s 2
ttotal = 2(tup) = 2(142 s) = 284 s
dx = vixt = (975.1 m/s)(284 s) = 2.77 x 105 m
(max range occurs at ttotal!)
2
dy = viyt + ½ at = (1392.6 m/s)(142 s) + ½ (–9.8 m/s2)(142 s)2 = 9.89 x 104 m
(max height occurs at tup!)
4.
N=W
f = N
25 kg
Fa = ?
W = mg
(a)
(b)
W = mg = (25 kg)(9.8 m/s2) = 245 N
N = W = 245 N
Fa = fs = sN = (0.55)(245 N) = 135 N
x-direction:
y-direction:
FNET = ma
N = W = 245 N
Fa – fk = ma
fk = kN = (0.30)(245 N) = 73.5 N
200 N – 73.5 N = (25 kg)(a)
a = 5.06 m/s2
8
(c)
N=W
f = N
Fa = ?
25 kg
30
o
W = mg
x-direction:
y-direction:
o
Fax = 200 cos 30 = 173.2 N
Fay = 200 sin 30o = 100 N
FNET = ma
N + Fay = W
Fax – fk = ma
N = W – Fay = 245 – 100 = 145 N
fk = kN = (0.30)(145 N) = 43.5 N
173.2 – 43.5 N = (25 kg)(a)
a = 5.19 m/s2
5.
Fax = Fa cos  = (75 N)(cos 50o) = 48.2 N
Wk = Faxd = (48.2 N)(150 m) = 7231 J
P = Wk/t = (7231 J)/(25 s) = 289 W
6.
(a)
(b)
7.
PEelastic = PEgravitational + KE
½ kx2 = mgh + ½ mv2
½ (2000 N/m)(0.25 m)2 = (1 kg)(9.8 m/s2)(1.25 m) + ½ (1 kg)(v2)
v = 10.0 m/s
PEelastic = PEgravitational + Ethermal
½ kx2 = mgh + fd
where…
f = N = W = mg
2
½ kx = mgh + mgd
½ (2000 N/m)(0.25 m)2 = (1 kg)(9.8 m/s2)(1.25 m) + (0.65)(1 kg)(9.8 m/s2)(d)
d = 7.89 m
m1v1i + m2v2i = m1v1f + m2v2f
v1i + v2i = v1f + v2f
3 m/s + 0 = 0.5 m/s + v2f
v2f = 2.5 m/s, to the right
(since m1 = m2, and thus the masses cancel!)
8.
f = 3 rev/s = 3 Hz
 = 2f = 2(3 Hz) = 18.8 rad/s
T = 1/f = 1/3 = 0.33 s
vt = 2r/T = 2(0.8 m)/(0.33 s) = 15.2 m/s
ac = v2/r = (15.2 m/s)2/(0.8 m) = 290 m/s2 (towards center of circle)
Fc = mac = (0.5 kg)(290 m/s2) = 145 N
9.
(a)
(b)
(c)
f = i + t = 0 + (2 rad/s2)(10 s) = 20 rad/s
 = it + ½ t2 = 0 + ½ (2 rad/s2)(10 s)2 = 100 rad
(100 rad)/(2 rad/rev) = 15.9 rev
9
10.
(a)
(b)
= –F1 r1 sin 1 + F2 r2 sin 2
(since clockwise torques are negative!)
= –(5 N)(4 m)(sin 30o) + (8 N)(3 m)(sin 40o) = 5.43 N.m
1 mL2
I = 12
(thin rod)
1 )(1 kg)(10 m)2 = 8.33 kg.m2
I = ( 12
(c)


11.
(a)
(b)
= I
5.43 N.m = (8.33 kg.m2)()
= 0.65 rad/s2
I = ½ mr2 = ½ (100 kg)(4 m)2 = 800 kg.m2 (disk-shaped merry-go-round)
I = mr2 = (25 kg)(3 m)2 = 225 kg.m2 (boy at initial location)
I = mr2 = (25 kg)(0 m)2 = 0 kg.m2
(boy at final location)
Li = Lf
(I1 + I2i)i = (I1 + I2f) f
(800 + 225 kg.m2)(0.70 rad/s) = (800 + 0 kg.m2)(f)
f = 0.90 rad/s
KErotational = ½ Iii2 = ½ (800 + 225 kg.m2)(0.70 rad/s)2 = 251 J (initial)
KErotational = ½ Iff2 = ½ (800 + 0 kg.m2)(0.90 rad/s)2 = 324 J (final)
12.
Heat ice from –10oC to 0oC:
Q = mCT = (2 kg)(2090 J/kg oC)(10oC) = 41,800 J
Change ice to water:
Qf = mLf = (2 kg)(3.33 x 105 J/kg) = 666,000 J
Heat water from 0oC to 25oC:
Q = mCT = (2 kg)(4186 J/kg oC)(25oC) = 209,300 J
Combining the above:
Total heat added = 917,100 J
13.
(a)
(b)
(c)
F = –kx
–(5 kg)(9.8 m/s2) = –(k)(0.10 m)
k = 490 N/m
m
5 kg
= 0.63 s
T  2
 2
k
490 N/m
L
T  2
g
L
14.
15.
gT 2
4 2

(9.8 m/s 2 )(0.63 s) 2
4 2
= 0.099 m
d = vt
t = d/v = (2)(450 m)/(1530 m/s) = 0.59 s
v = f
v 3 x 10 8 m/s
= 5.77 x 1014 Hz
f 
 5.2 x 10 7 m
(for sound to travel to bottom and back!)
T
1
1
= 1.73 x 10–15 s

f 5.77 x 1014 Hz
10
16.
(a)
(b)
(c)
ni sin i = nr sin r
1.61 sin 28.7o = 1.33 sin r
r = 35.5o
n
1.33
sin  c  r 
n i 1.61

c = 55.7o
c
n
v
c
3 x 10 8 m/s
= 1.86 x 108 m/s
v glass 

n glass
1.61
v water 
17.
(a)
(b)
(c)
(d)
18.
(a)
(b)
c
n water

3 x 10 8 m/s
= 2.26 x 108 m/s
1.33
f = ½ c = ½ (25 cm) = 12.5 cm
1 1
1


f di do
1 1 1
1
1
 


 di = 33.3 cm, real
d i f d o 12.5 cm 20 cm
d
33.3 cm
= –1.67, larger, inverted
m i 
do
20 cm
1 1 1
1
1
 


 di = –7.69 cm, virtual
d i f d o  12.5 cm 20 cm
d
 7.69 cm
= 0.38, smaller, upright
m i 
do
20 cm
1 1 1
1
1
 


 di = –3.33 cm, virtual
d i f d o  5 cm 10 cm
d
 3.33 cm
= 0.33, upright, smaller
m i 
do
10 cm
1 1 1
1
1
 


 di = 10 cm, real
d i f d o 5 cm 10 cm
d
10 cm
= –1, inverted, same size
m i 
do
10 cm
F
Gm1m 2
2

(6.67 x 10 11 Nm 2 /kg 2 )( 2 kg)(3 kg)
2
= 8.17 x 10–10 N, attractive
r
(0.70 m)
–19
q1 = 2(1.6 x 10 C) = 3.2 x 10–19 C, q2 = 4(–1.6 x 10–19 C) = –6.4 x 10–19 C
kq q
(9 x 109 Nm2 /C 2 )(3.2 x 10 19 C)( 6.4 x 10 19 C)
F  12 2 
r
(0.70 m) 2
= –3.76 x 10–27 N, attractive
11
19.
(a)
E1 
kq1
E2 
kq 2
r12
r2 2
ENET =
(b)
(c)


(9 x 10 9 Nm 2 /C 2 )( 2 x 10 9 C)
(0.06 m) 2
(9 x 10 9 Nm 2 /C 2 )(1 x 10 9 C)
= –5000 N/C, to the right
= 5625 N/C, downward
(0.04 m) 2
E12  E 2 2  (5000 N/C) 2  (5625 N/C) 2 = 7526 N/C
E 
 5625 
at   tan 1  2   tan 1 
 = 48.4o  360o – 48.4o = 311.6o
E
5000


 1
–12
Felectric = qoE = (1 x 10 C)(7526 N/C) = 7.53 x 10–9 N at 311.6o
kq1 (9 x 10 9 Nm 2 /C 2 )( 2 x 10 9 C)
V1 

= –300 V
r1
(0.06 m)
kq 2 (9 x 10 9 Nm 2 /C 2 )(1 x 10 9 C)

= 225 V
r2
(0.04 m)
Vtotal = –300 + 225 = –75 V
V2 
20.
(a)
(b)
q = CV = (1000 x 10–6 F)(9 V) = 0.009 C
PEelectric = ½ CV2 = ½ (1000 x 10–6 F)(9 V)2 = 0.0405 J
21.
(a)
(b)
(c)
V = IR = (6.25 A)(17.6 ) = 110 V
P = IV = (6.25 A)(110 V) = 687.5 W
E = Pt = (0.6875 kW)(30 h) = 20.625 kWh
(20.625 kWh)($0.10/kWh) = $2.06
22.
30 
3 V, 0.1 A
30 
3 V, 0.1 A
10 20 
0.1 A, 1 V 0.1 A, 2 V
30 
3 V, 0.1 A
15 
0.2 A
3V
15 
0.2 A
3 V

6V
6V
12
15 
0.2 A, 3 V
15 
0.2 A
3V
30 

I
V
6V

 0 .2 A 
R EQ 30 
6V
P1 = I1V1 = (0.2 A)(3 V) = 0.6 W
P3 = I3V3 = (0.1 A)(1 V) = 0.1 W
23.
(a)
(b)
24.
(a)
6V
P2 = I2V2 = (0.1 A)(3 V) = 0.3 W
P4 = I4V4 = (0.1 A)(2 V) = 0.2 W
F = qvB sin  = (0.05 C)(2500 m/s)(0.5 T)(sin 90o) = 62.5 N, to the north
F = ILB sin  = (10 A)(2 m)(0.5 T)(sin 90o) = 10 N, to the west
[AB(cos )]
,
t
B
emf   NA(cos )
t
emf   N
A = r2 = (0.30 m)2 = 0.283 m2
 0.25  0.75 T 
emf  (1)(0.283)(cos 0 o )
  2.83 V
0.05 s


(b)
(c)
V 2.83 V

 0.94 A
R
3
clockwise
I