Peoples Physics Book Version-3

http://www.ck12.org Concept 27. Equations and Fundamental Concepts

sin(θ) =b/c→b=c·sin(θ)

cos(θ) =a/c→a=c·cos(θ)

tan(θ) =b/a→b=a·tan(θ)

c^2 =a^2 +b^2

180 ◦=πradians

Ccircle= 2 πR

Acircle=πR^2

Vs phere= ( 4 / 3 )πR^3

Vcylinder=πR^2 h

IfXis any unit, then...

1 mX= 0 .001 X= 10 −^3 X

1 μX= 0 .000001 X= 10 −^6 X

1 nX= 0 .000000001 X= 10 −^9 X

1 kX=1000 X= 103 X

1 MX=1000000 X= 106 X

1 GX=1000000000 X= 109 X

Ifax^2 +bx+c=0 , then...

x=

−b±

√

b^2 − 4 ac

2 a

% difference = |(measured – accepted) / accepted |×100 %

vector dot product:a·b=abcosθ(product is a scalar)—θis angle between vectors

vector cross product:a×b=absinθ(direction is given by RHR)

Kinematics Under Constant Acceleration

4 x=xf inal−xinitial

4 (anything)=final value−initial value

vavg= 4 x/ 4 t

aavg= 4 v/ 4 t