Cheatography

# Physics IX Cheat Sheet by Ayesha Talib

Formula sheet for students of class IX

### MOTION

 displa­cement m distance m speed m/s velocity m/s aceler­ation m/s2
speed (v) = s/t
average speed = total s/total t
velocity = d/t
average velocity = total d/total t
accele­ration = v-u/t
v = 2πr/t
v = u+at
s = ut+1/2at2
v2 = u2+2as

### FORCE AND LAWS OF MOTION

 inertia kg force kgm/s2 or N momentum kgm/s mass kg
F = ma
p = mv
change in momentum = mv-mu
m
``1``
v
``1``
+m
``2``
v
``2``
=(m
``1``
m
``2``
)v

### GRAVIT­ATION

 weight N mass kg pressure Pa or N/m2 accele­ration due to gravity m/s2 density g/cm3
F = GMm/d2
g = GM/R2
W = mg
W
``m``
= 1/6 W
``e``

(thrust) F = mg
Weight­-up­thrust = m
W = m+upthrust
h = 1/2gt2
v2 = 2gh
v = gt

### WORK AND ENERGY

 work J energy J power W
work = Fs
E
``p``
= mgh
E
``k``
= 1/2mv2
power = W/t /// power = E/t
average power = total E/total t

### SOUND

 wavelength m frequency Hz time period s loudness dB intensity W/m2
Nu = 1/T
v = λ/T
v = Nuλ