Formulas Flashcards
Friction
(F)friction = µ x (F)normal
-µ: coefficient of firction
-(F)normal= mg / (F)normal= mgCos(θ)
-(F)net= (F)applied - (F)friction
Parallel
(F)parallel = F - mgSin(θ)
(F)down
(F)down = mgSin(θ)
Momentum
Momentum = mass x velocity
P=mv
-P: Kgms^-1
-m: Kg
-v: ms^-1
Density
ρ=m/v
-ρ: density (kgm^-3)
-v: volume (m^-3)
-m: mass (Kg)
*units can change (ex: gcm^-3, …)
Hooke’s Law
-Spring Force = -(Spring Constant) x (Displacement)
F=-kx
-F: force
-k: constant force (or spring constant)
-x: extension
Unit: Nm^-1
Stress
Stress= Restoring Force / Area
= F/A
Unit: Nm^-2
*(also Pascal (Pa) formula and units)
Strain
Strain= Change in lenght / Original lenght
ε = ΔL / L
Or
=dx / L
No unit, instead uses porcentage %
Stress
Stress = Force / Area
σ = F / A
(Or
Stress= Constant x Strain?)
Springs connected in series
1/Ktotal = 1/k1 + 1/k2 + 2/k3 …
Potential Energy of a Spring (P.E.)
Ee=1/2 ke^2
Or
E=1/2Fx
-Ee: potential energy - Joules (J)
-k: spring constant - Newtons/meter (N/m)
-e: increase in lenght - metre (m)
Young’s modulus for materia
Y=(F/A) / (ΔL/L)
Or
Y= Stress / Strain
K
K=Lenght×Strain
Resitence
R= ρxL/A
Unit= Ohms (Ω)
Power
P= v^2/R
Unit: Watts (W)
