Physics 152
Final Exam
_
_
(Name)
1.
Find the force on a charge on q1 = 4x10-6coulombs at the apex
of an equilateral triangle with -6
sides of 20 cm. if the other two
corners are occupied by q2=+3x10 coulombs and q3=-5x10-6coulombs
respectively. (Specify
You are allowed to work together; however, your answers should not be carbon-copies of each other work. SHOW ALL
YOUR WORK! For full credit, provide explanations when requested. This exam will count as 50 points (half of the value of
an in-class exam).
27.1
From Wiens displacement law,
(a)
T=
0.
2898 102 m K
m ax
=
0.
2898 102 m K
970 109 m
= 2. 103 K ,or 3000 K
99
(b) T =
0.
2898 102 m K
m ax
=
0.
2898 102 m K
145 109 m
= 2. 104 K ,or 20000 K
00
27.5
E = hf =
hc
which yields
(a)
E=
63
( 6. 10
34
=
E=
25.9
This patient needs a lens that will form an upright, virtual image at her near
point (60.0 cm) when the object distance is p = 24. cm . From the thin lens
0
equation, the needed focal length is
f=
25.12
0
0
pq ( 24. cm ) ( 60. cm )
=
= + 40. cm
0
p+
1-20.23
(a) To oppose the motion of the magnet, the magnetic field generated by the
induced current should be directed to the right along the axis of the coil. The
ef o i
current must then be l tt r ght through the resistor.
(b) The magnetic field produce
19.1
The direction in parts (a) through (d) is found by use of the right hand rule. You
must remember that the electron is negatively charged and thus experiences a
force in the direction exactly opposite that predicted by the right hand rule for a
positi
t
p
3. s
0
26.3
t= t =
p
26.4
(a) Observers on Earth measure the time for the astronauts to reach Alpha
Centauri as t = 4. yr . But these observers are moving relative to the
42
E
1 ( v c)
2
=
1-( 0. )
80
2
= 5. s
0
astronauts internal biological clock an
28.11
The energy of the emitted photon is
E =
hc
626
( 6. 10
34
=
J s) ( 2. 108 m s) 1 nm
998
9
656 nm
10 m
1 ev
1. 1019
602
89
= 1. eV
J
This photon energy is also the difference in the electrons energy in its initial and
final orbits. The energies of
Physics 152
Exam 4
_
(Name)
1.
A particular subatomic particle has an expected lifetime
(average value) of 2 x 10-7 seconds when it at rest or moving
slowly. Its rest mass is 80 times as massive as an electrons.
When it emitted from a nucleus in a particu
Physics 152
Sample exam 2
1.
A small light rests on the bottom of a swimming pool 1.6 meters deep.
Though the light radiates uniformly in all directions, from above the
light emerging from the water (n=1.34) surface forms a circle. What is
the diameter of
24.3
(a) The distance between the central maximum and the first order bright fringe
L
ybright
=
is y = ybright
, or (Note, it is safer to not use the
m =1
m =0
d
approximation used here that tan=sin)
y =
L
d
1
( 546. 10
=
9
20
) (1. m ) = 2. 10
62
m
3
3
23.7
The radius of curvature of a concave mirror is positive, so R = + 20. cm . The
0
mirror equation then gives
0
0
121
1
1 p 10. cm
( 10. cm ) p
=
=
, or q =
q R p 10. cm p ( 10. cm ) p
0
0
p 10. cm
0
(a) If p = 40. cm , q = + 13. cm and M =
0
3
q
13.
Best Answer: The electric field of an electron equals the force divided
by the charge. The charge of an electron is -1.6 x 10A-19 Coulombs
E = F/q
From there we get:
a)
F = Eq
F = (295 NICK-1.6 x 10A-19 C)
F = -4.72 x 10A-17 Newtons
We also know that F =
A proton accelerates from rest in a uniform
electric field of 670 N/C. At some later time,
its speed is 1.20?
A proton accelerates from rest in a uniform electric field of 670 NIC. At some
Answers
later time, its speed is 1.20 106 mls.
(a) Find the magnit
Step 1
(a) The force exerted on the proton of charge qp = +e by the electric eld has magnitude F = qu = eE
where E is the magnitude of the electric eld and F is the magnitude of the force. Newtons second law
gives the acceleration a of the proton in terms
A proton accelerates from rest in a uniform electric eld of 621 MC. At some later time, its speed is
1.11 x 105 m/s.
(a) Find the magnitude of the acceleration of the proton.
(b) How long does it take the proton to reach this speed?
(c) How far has it mov
How do i find the electric field at a specific
position (2.5, O) ?
Three point charges are aligned along the 3: axis as shown in Figure P15.49.
Find the electric field at the position 3: = +2.5 m, y :0
what is the direction:> options
The field is in the -
9 Physics problem help?
if the electric field strength in air exceeds 3.0 multiplied by 106 MG, the air
becomes a conductor. Using this fact, determine the maximum amount of
charge that can be carried by a metal sphere 1.2 m in radius. (Hint: Review
prope
+600pC P Ea +1.50 pc 4000C
_ =2- _ _
O (0- +
:m 02 .> :02 :03
i inVl : I
(a) Taking to the right as positive, the resultant electric eld at point P is given by 5
ER = E1 + 3 E2 5
ke|q1| ke|t73| kellhl
2 +
r1 r32 r22
6 6 6
(839 x 109 N _ m2/C2)[6.00
Units! kiiograms, meters, amps (l), teslas (T), torque cfw_Nam, kilo, milli, micro, nano; pa = 41: x107 T-m/A
I. An electron g = 1.6 x 10 C) is traveling east (+x) with an instantaneous velocity of
2.5 x 105 refs when it enters a uniform magnetic eld B of
Phys 152 Exam 1 Practice Problem
CH15
1. Experimental evidence indicates that . a
A) charge is quantized and conserved. Wt aura-'5; oi? )Cii
B) charge is quantized but not conserved.
C) charge is conserved but not quantized.
D). charge is neither quantize
Phys 152 Fall 2016 Exam 1 Name k6?)
1. A particular nucleus of the element plutonium contains 94 protons and 150 neutrons. What is the
magnitude of the force from the nucleus (11;) on a single elect on (12) that Is at a distance of
ti: 0. 563 x 10 In from