physics formulae Flashcards
(185 cards)
1
Q
speed
A
distance/time
unit: m/s
2
Q
velocity
A
displacement/time
unit: m/s
3
Q
2 formulae of acceleration
when given velocity, initial velocity, final velocity
A
velocity/time
v-u/t
unit: m/s²
4
Q
T, time
A
1/f
5
Q
1st eq of linear motion
velocity equals??
when given initial velocity, acceleration
A
u + at
6
Q
2nd eq of linear motion
displacement, s equals??
when given final velocity, time
A
1/2(u + v)t
7
Q
3rd eq of linear motion
displacement, s equals??
just guess bitch
A
ut + 1/2at²
8
Q
4th eq of linear motion
velocity squared equals??
when given displacement
A
u² + 2as
9
Q
gradient of displacement-time graph represents
A
velocity
10
Q
area under graph of velocity time graph is
A
distance travelled
11
Q
gradient of velocity time graph is
A
acceleration
12
Q
formula for momentum
A
mass x velocity
unit: kg/ms
13
Q
formula for elastic collision
A
m1u1 + m2u2 = m1v1 + m2v2
14
Q
formula for inelastic collision
A
m1u1 + m2u2 = (m1+m2)v
15
Q
formula for explosion
A
0 = m1v1 + m2v2
hence, m1v1 = -m2v2
16
Q
formula for force, F
A
mass x acceleration
unit: N or kg/ms²
17
Q
formula for force
when given final velocity and time
A
mv-mu/t
18
Q
net force
A
total force - frictional force
19
Q
impulse, I (2 eq)
when given force, mass, final velocity
A
Ft
mv-mu
unit: Ns or kg/ms
20
Q
impulsive force, F
A
mv-mu/t
21
Q
force is inversely proportional to
A
time
22
Q
weight, W
A
mass x gravitational acceleration (mg)
unit: N
23
Q
what is the value of g?
A
9.8 or 10 m/s²
24
Q
what is G?
A
universal gravitational constant
25
Newton's law of gravity
F = Gm1m2/r²
26
gravitational force of body on Earth's surface, F
GMm/R²
M = mass of Earth (5.98 x 10^24)
R = radius of Earth
27
gravitational force between Earth & Satellite, F
GMm/(R + h)²
28
gravitational force between Earth & Sun, F
GMm/r²
29
centripetal force, Fc
mv²/r
30
determining mass of sun or earth, M
4π²R³/GT²
| values vary according to sun or earth
31
acceleration of satellites
v² / r
32
force = ma AND also?
mg
33
relationship between orbital period, T and radius of orbit
T³/r³ = 4π²/GM
34
kepler's 3rd law eq
(T1)² / (R1)³ = (T2)² / (R2)³
35
speed of satellite
| hint: centripetal force = gravitational force
v = square root GM/r
36
escape velocity
| hint: kinetic energy = weight
v = square root 2GM/R
37
another eq for v
square root 2gG
38
reading a thermometer temperature
l(θ) - l(ice point) x 100 C
39
heat capacity, Q
Cθ
| unit: J/C
40
specific heat capacity, c
mcθ
| unit: J/kg/C
41
heat capacity, Q also equal to?
Pt
42
hence, Pt equal to?
mcθ
43
unit of power, P
watt, W
44
specific latent heat, l
ml
45
when heat transfer involved
mcθ=ml
46
amount of heat needed to heat ice at 0 C to water at
| 25 C
mL + mcθ
47
what is mL stand for
heat needed to change ice at 0 C to water at 0 C
48
what is mcθ stand for
heat needed to change water at 0 C to water at 25 C
49
boyle's law
P inversely proportional to V
50
PV equal to
constant, k
51
eq for boyle's law
P1V1 = P2V2
52
pressure law
P ∝ T
53
eq for pressure law
P1/T1 = P2/T2
54
Charles' law
V ∝ T
55
eq for Charles' law
V1/T1 = V2/T2
56
frequency, f of waves
number of oscillations/time taken
| herts, Hz
57
wavelength, λ
v = fλ
58
when you want to compare 2 velocity of wave
v1/λ1 = v2/λ2
59
capital V stands for
volume
60
when you want to compare 2 frequency of wave
f1λ1 = f2λ2
61
that one experiment with two speakers, find distance and whatever
λ = ax (over)
| D
62
what does D stand for
distance between screen and double slit
63
what does x stand for
distance between fringes
64
what does a stand for
separation of slit
65
that diagram where they echo at a wall, how do to find distance
velocity sound x time. (over)
| 2
66
electromagnetic spectrum
G - X - U - visible light - I - M - R
67
going up electromagnetic spectrum, the frequency
increases
68
going down electromagnetic spectrum, the λ
decreases
69
speed of light, c
fλ
70
how many formulas for refractive index, n
4
71
when given angle of incident and refraction, eq to find n is
sin i/sin r
72
when given speed of light, eq to find n is
c/v
| v = speed of light in medium
73
value of speed of light
3 x 10^8
74
when given real depth & apparent depth, eq to find n is
real depth/apparent depth
75
when given critical angle, eq to find n is
1/sin c
76
power of lenses, P. if question mintak ans in metre
1/f
77
power of lenses, P. if question mintak ans in cm
100/f
78
what is unit of P
diopter (D) or m-1
79
power of convex lens
+ve
80
power of concave lens
-ve
81
linear magnification, m
image distance/object distance Or
| image height/object height
82
when they wanna compare linear magnification, and they give distance & height
image distance. = image height
| object distance. object height
83
focal length, the formula start with 1/f
1/u + 1/v
84
focal point of convex lens
+ve
85
focal point of concave lens
-ve
86
for real image, v (object distance) is
+ve
87
for virtual image, v is
-ve
88
for concave lens, v is always
-ve
89
for convex & concave lens u is always
+ve
90
focal length of compound microscope
| compare between fo and fe
fo < fe
91
magnification of compound microscope
mo x me
92
focal length of astronomical telescope
| compare between fo and fe
fo > fe
93
magnification of astronomical telescope
fo/fe
94
L, distance between 2 lenses
fo + fe
95
FORM 5
bismillah
96
in a graph of Fy against Fx, find magnitude of Fx
F cos θ
97
find magnitude of Fy
F sin θ
98
sine rule
x/sin opposite x = y/sin opposite y
99
cosine rule
square root x² + y² - 2xy cosθ
100
extension of spring
final length - initial length
101
hooke's law
force applied ∝ extension of spring
102
k stands for
spring constant
103
graph of Hooke's law x against F
directly proportional
104
formula Hooke's law
F = kx
105
according to graph, the limit is
gradient
106
the stiffness of spring, the spring constant refer to
gradient
107
area under graph of Hooke's law
elastic potential energy
108
elastic potential energy
1/2 Fx
109
extension of springs arranged in series
x + x = 2x
110
extension of springs arranged in parallel
x/2
111
tension of springs arranged in parallel
F/2
112
formula for P, liquid pressure
hpg
113
h stand for
depth of liquid
114
p stand for
density of liquid
115
S.I unit for P
Pa
116
1 Pa equal to
1 Nm-2 or 1 kg m-1 s-2
117
comparing liquid pressure at 2 different points
P1 = P2
| hence, h1p1 = h2p2
118
atm pressure at sea level
100 000 Pa or 100 kPa
119
actual pressure
hpg + P(atm)
120
millimetres of mercury
mm Hg
121
pascal's principle
F2/A2 = F1/A1
122
value for multiplying factor
A2/A1
123
volume of solid in water is same as
volume of water displaced
124
volume of water displaced
V = Ah
125
formula for density, p
m/v
126
force acting on surface of submerged solid
F = PA
127
buoyant force, F equal to
pVg
128
floating object
compare its W to Fb
resultant force
W = Fb
| resultant force = 0
129
sinking object
compare its W to Fb
resultant force
W > Fb
| resultant force = downwards
130
object rising up
compare its W to Fb
resultant force
W < Fb
| resultant force = upwards
131
formula for electric field strength, E at any given point in an electric field
F/q (electric force/quantity of electric charge)
132
s.i unit for E is for the first formula is
N/C
133
formula for electric field strength, E produced by 2 parallel charged plates
V/d
134
s.i unit for E is for the second formula is
V/m
135
s.i unit for charge is
coloumb, C
136
formula for current, I
Q/t
137
S.I unit for current is
ampere,(A)
| C/s
138
formula for potential difference, V if given work done
W/Q
139
formula for potential difference, V if given energy transferred
E/Q
140
s.i unit for V
volt, V
| J/C
141
value of charge of an electron
1.6 x 10^ -19 C
142
1 C is equivalent to how many electrons
6.25 x 10^18 electrons
143
ohms law
V = IR
144
current flowing through resistor in a series circuit
I = I1 = I2 = I3
145
potential difference in a series circuit
V = V1 + V2 + V3
146
effective resistance in a series circuit
R = R1 + R2 + R3
147
current flowing through resistor in a parallel circuit
I = I1 + I2 + I3
148
potential difference in a parallel circuit
V = V1 = V2 = V3
149
effective resistance in a parallel circuit
1/R = 1/R1 + 1/R2 + 1/R3
150
compare resistivity of Cu, constantan and nichrome
Cu has lowest resistivity
| Nichrome has highest resistivity
151
formula of resistance, R when given length and area of cross-section of wire
pl/A
| p= resistivity of material
152
formula for ε, emf
E/Q
153
S.I unit for emf
volt, (V)
| J/C
154
formula for internal resistance, Ir
ε - V
155
find value of ε when given external resistance and internal resistance
ε = I (R + r)
156
emf of cells arranged in series
re = r + r + r + r
157
emf of cells arranged in parallel
1/re = 1/r + 1/r + 1/r
158
value of current in parallel circuit when given ε and external resistance
ε / R + re
159
formula for electrical energy when given current
VIt
160
formula for electrical power, P when given electrical energy
E/t
161
formula for P, when given current
VI
162
s.i unit for P
watt (W)
| J/s
163
formula derived from ohm's law and P when given V
V²/R
164
formula derived from ohm's law and P when given I
I²R
165
total electrical energy is measured in
1 kWh
166
step down transformer, compare Ns and Np
Ns < Np
167
step up transformer, compare Ns and Np
Ns > Np
168
relationship between Ns, Np, Vs and Vp
Vs/Vp = Ns/Np
169
formula for efficiency, fancy n
output power/input power x 100
170
relationship between output power and input power
VpIp = VsIs
171
relationship between Vs and P
VsIs = P
172
formula of electrical potential energy, E of an electron
eV
173
relate electrical potential energy with kinetic energy
eV = 1/2mv(max)²
174
amplification factor of transistor can be found in graph of Ic against Ib by
looking at the gradient
175
concept of potential divider, how find V(out)
R2. over. x V(in)
| R1 + R2
176
what happens to A and Z in an alpha decay
A - 4
| Z - 2
177
what happens to A and Z in beta decay
A remains same
| Z + 1
178
what happens to A and Z in gamma decay
remains same
179
concept of half life, what happens No
No/2 - No/4 - No/8
180
formula to find no of half life, n
t/half life
181
formula for A, final activity
(1/2)^n x Ao
182
mass defect, m when given mass before & after fission
mass before fission - mass after fision
183
formula for energy released during nuclear reaction, E
mc²
184
value of atomic mass unit, amu
1.667 x 10^ -27 kg
185
how to convert mass defect in amu to kg
amu x 1.667 x 10^ -27 kg
