# Physics

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1. translational motion:
distance, velocity, acceleration. time
x = x0 + v0t + (1/2)at2
2. translational motion:
velocity, acceleration and distance
v2 = v02 + 2ax
3. translational motion:
velocity, acceleration and time
v = v0 + at
4. how does a projectile stay in motion? what keeps it in motion?
inertia
5. peak height of a projectile
v0 = sin(0) - sq.rt.(2gh)
6. horizontal distance traveled of a projectile
x = vt . cos(0)
7. peak velocity
no velocity, but acceleration = 10
8. PE and KE of projectile object at its peak
• PE is maximized
• KE is minimized

(energy must be conserved)
9. projectile path is independent of....
mass
10. two objects launched with the same velocity will...
hit the ground at the same moment
11. what determines the time of flight?
vertical velocity
12. range of projectile is maximized at what angle from the horizontal?
450
13. symmetry of projectile says what? (speed wise)
upward mirrors downward -

initial speed = final speed
14. air resistance is greater on (surface area, shape, and speed)
• larger surface area
• irregularly shaped
• greater speed
15. does mass affect force or path of air resistance
force = no

path = yes
16. how does greater mass affect air resistance
force is the same, so it decreases acceleration

(F=ma)
17. centripetal force (equation)
F = m . v2/r
18. inertia
tendency of an object to stay in present state of motion

(keeps projectile in motion)
19. law of universal gravitation
F = G(m1m2)/r2
20. friction points in what direction?
always parallel to surface
21. equation for torque
t = F r sin0
22. if the board has mass, what do you do with torque?
F=mg at center of board
23. equation for work (not for gases)
W = Fd cos0
24. what direction is friction (relative to work)?
friction does negative work!
25. work done lifting an object
W = Fd = mg x h
26. what is gravitational potential energy?
work done by gravity:

change PE = -W
27. energy and power
energy = work + heat

so, P = (w + q)/s
28. 1 revolution is equal to
2 pi r
29. equation for angular momentum
L = l x m x v

l = lever arm, mv = linear momentum
30. elastic collision
mechanical energy is conserved
31. inelastic collision
mechanical energy is lost to internal energy (heat)
32. perfect inelastic collision
2 objects stick together
33. reverse inelasitc collisions (object dissipates into 2 sep. objects). In what direction do they travel
opposite to each other
34. ex: man standing on a board and jumps off

what do you need to consider when determining their final positions?
move in opposite directions

consider their centers of gravity
35. what is impulse?
change in momentum
36. Machine: inclined plane (how is work minimized?)
straight up: W = ugh

ramp: W = mg x sin x h
37. What is theta equal to in the ramp
height of ramp / distance of the ramp

the greater the distance (d) the smaller the angle, the less work needed
38. Machine: lever (torque)

what does F need to equal to lift mass?
F = mg in opposite direction
39. How do you decrease the force required to life the object?
increasing the lever arm

(doubling lever arm, reduces force by a factor of 2)
40. In a pulley, what is the tension in the rope?
constant

Tension = Force
41. In a double pulley system, what is the force required to lift mass m?
F = T

T = 2mg

F = (mg)/2
42. alpha decay
2 protons, 2 neutrons
43. traveling of alpha particle
not far

stopped by skin, paper
44. beta decay
expulsion of an e-
45. positron
B+ is emitted (-1 atomic #)
46. electron capture
gain e- (-1 atomic number
47. frequency of a gamma particle
high frequency particle
48. rest mass energy
E = mc2
49. fussion combining 2 (?) from (?)
combining 2 nuclei

from a heavier nucleus
50. fission
splitting a single nucleus into 2 lighter nuclei
51. where does energy for fusion and fission come from?
mass defect
52. density formula
density = m/v
53. density constant for gases and liquids?
constant for liquids and solids

change for gases, because they are compressible
54. What is specific gravity?
density of a substance compared to density of water
55. so specific gravity of water is
1
56. formula for fluid pressure
P = F/A
57. Do fluids at rest have uniform density in a sealed container?
yes
58. What is the pressure experience by fluids at rest with uniform density?
P = density x g x y

y = depth of fluid
59. Where is pressure greatest for a fluid at rest?
greatest depth (P=pgy)
60. What if you have many fluids layered in a sealed container?
P = (pgy)1 + (pgy)2 + (pgy)3...........
61. What is the pressure of a fluid at rest with uniform density in an open container
add atmospheric pressure to density x g x y
62. hydraulic lift (equation)
pressure is transferred completely:

F1/A1 = F2/A2
63. What is the velocity of a fluid flowing (if you don't know rate or area)?
v = sq.rt (2gh)
64. buoyant force
upward force acting on a submerged object
65. what is buoyant force equal to? (not equation)
weight of fluid displaced by submerged object
66. equation for buoyant force
FB = (density of fluid) x (volume) x (g)
67. floating object -
submerged portion of object =

density of object/density of fluid
68. How much of an object will float in water if its specific gravity is 0.4?
60%
69. does buoyant force change with depth?
No
70. What is the apparent mass on an object (when it is submerged)?
mass of the fluid displaced

thats why we weigh so little in water
71. equation for fluid flow
Q = (area)(volume)
72. does fluid flow faster in a wider pipe, or a more narrow pipe?
narrow
73. ideal fluid flows at a constant rate
K = Pressure + (density)(g)(h) + (1.2)(p)(v2)

K is constant, specific to fluid in a flow
74. surface tension and temperature
increase temperature = weaker surface tension
75. formula for stress
force/area
76. formula for strain
change in dimension/original dimension
77. what are stress and strain
stress is done on an object

strain is how the object responds
78. modulus of elasticity
stress/strain
79. What is Coloumb's law? (equation) What does it mean?
describes force between two charges

F = k (q1q2) / r

k = 9 x 109
80. Coloumb's law resembles what? But?
gravitational force (G)(m1m2)/(r2)

• but, gravitational force is attractive
• electrical force is repulsive
81. electric field - in what way are the lines drawn? What does the length of the line indicate?
(+) ----------------> (-)

length = strength

(smaller is stronger)
82. What is the electric field created by charge Q?
E = k x (Q)/(r2)
83. What is the force felt by charge q in the electric field E?
F = E x q
84. What makes and feels the field?
Q makes the field

q feels the field

[F = k x (Qq)/(r2)
85. What is the potential energy of of the charge in electric field?
Potential energy (U) = force x displacement (like ugh)

U = Eq x h
86. How does potential energy change when moving perpendicular to electric field?
doesn't change

same way that moving parallel to surface of the earth doesn't change gravitational potential energy
87. What is an electric dipole?
created by 2 opposite charges with equal magnitude
88. (+) and (-) fall/rise to lower/higher potential?
+ charge falls to a lower potential

- charge rises to a higher potential
89. high/low potential and +/- potenital
• high potential = + potential
• low potential = - potential
90. How do we measure movement of a charge?
current (A)
91. So, what is current? (How is it measured)
Coloumbs/second
92. Current flows in what direction (relative to potential energy)
current flows from high potential to low potential
93. In what direction does current flow (relative to electron flow or electron velocity)?
current moves in opposite direction of e- flow
94. conducting electricity: what are good conductors and poor conductors?
• good = allow e- to flow freely [metals]
• poor = hold e- tightly in place [resistors]
95. What is induction?
charging a conductor
96. circuit equations: current, voltage, resistance, capacitance
V = IR

I = Q/t

C = Q/V
97. what is capacitance?
ability to store charge per unit voltage [Q/V]
98. voltage is the same thing as...... and it depends on
potential energy

depends on distance
99. plates that are further apart will have greater/less voltage and capacitance?
greater voltage

less capacitance
100. What is a capacitor?
temporarily stores energy in a circuit
101. What is the separation of charges in a capacitor?
emf between the plates
102. what is resistance?
resistance to flow of charge
103. resistance is directly proportionate to what?
length of wire

[R = density x (length/area)]
104. resistance and temperature
resistance increases with temperature

[thermal oscillations impede with flow]
105. Kirchoff's Rules:
- amount of current flowing in and out
- voltage around the circuit
-battery
- amount of flow in = amount of flow out

- votalge around any path in circuit must sum = 0

- battery adds energy to circuit
106. How does battery add energy to the circuit?
increases voltage from one point to another

107. Diaelectric constant (K)
substance between plates of a capacitor

• -must be insulator to separate charge
• -resists creating EF, in order to store energy
108. Resistors in series/parallel

what is constant?
series = add [current is constant]

parallel = 1/R [voltage is constant]
109. what is the terminal voltage? (equation)
V = emf - IR
110. AC Current - what's going on?
e- don't move in one direction,

they oscillate back and forth
111. maximum current and maximum velocity in an AC Current
Vmax = sqrt.(2) x Vmax

Imax = sqrt.(2) x Imax
112. What creates a magnetic field?
charging electric field

currents (moving charges) creates the magnetic field
113. + and - of electric field corresponds to what in magnetic field?
north and south

north = + and south = -
114. In what direction do magnetic lines point?
north -------> south
115. Doess a stronger magnetic field have closer lines, or further apart?
closer lines = stronger fied
116. How does the KE of a particle moving through the magnetic field change?
no work done by the magnetic field, means no change in KE due to the magnetic field
117. What is magnetic force?
F = q x V x B x sin(0)
118. force is applied in what direction relative to both velocity and magnetic field
force is perpendicular to both velocity and magnetic field
119. What is the work done by magnetic force?
no work:

because it's perpendicular to velocity
120. What way does magnetic field act?
like centripetal force (mv2/r)

because charged particle moves in a circle
121. What will move through a magnetic field with a smaller radius: a proton or an electron
electron:

because it has smaller mass [F = mv2/r]
122. Right Hand Rule
thumb = direction of current

fingers = direction of magnetic field

palm = direction of force
123. What results from a change in magnetic field?
an electrical field
124. What happens to the mechanical energy in a magnetic field when it is changed and creates an electric field?
mechanical energy to create the field is dissipated as heat
125. What is the magnetic flux?
number of magnetic fields running through the loop
126. what does change in magnetic flux do?
induces an emf
127. What is a magnetic field generated by?
a moving charge
128. moving charge experiences what when moving through a magnetic field?
force = qvBsin0
129. In what direction is this force?
perpendicular to velocity and magnetic field (B)
130. At equilibrium, in an electric and magnetic field, what is the net force acting on a particle?
0

force from electric field = force from magnetic field

Eq = qvBsin(0)
131. How can we find the acceleration or distance of a particle traveling through an electric or magnetic field
F = ma

set force (Eq) or (qvbsin) = mass x acceleration

distance = (1/2)at2
 Author: natalieplana ID: 79687 Card Set: Physics Updated: 2011-04-19T12:35:20Z Folders: Description: Physics Show Answers: