VARIABLE Description
AProjected area relative to flow
ar | Centripetal acceleration at r |
at | Tangential acceleration at r |
Cd | Drag coefficient |
EEnergy
FForce at r or x, or Spring force (Hooke’s Law), or attractive force (Law of Gravitation), or Drag force (Drag force)
IMoment of inertia
kSpring constant
Ki,Kf | Initial and final kinetic energies |
m, m1, m2 | Mass |
NRotational speed
Ni, Nf | Initial and final rotational speeds |
PInstantaneous power
Pavg | Average power | |
r | Radius from rotation axis, or | |
Separation distance (Law of Gravitation) | ||
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tTime
vVelocity
vf, v1f, v2f | Final velocity |
vi, v1i | Initial velocity |
WWork
xDisplacement
Reference: 3.
Linear Mechanics (4, 1)
Equations:
F = m ⋅ a | Ki = | 1 | ⋅ m ⋅ vi | 2 | Kf = | 1 | ⋅ m ⋅ vf | 2 | W = F ⋅ x | |
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W = Kf – Ki |
| P = F ⋅ v | Pavg = | W |
| vf = vi + a ⋅ t | ||||
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Example:
Given: t=10_s, m=50_lb, a=12.5_ft/s^2, vi=0_ft/s.
Solution: vf=125_ft/s, x=625_ft, F=19.4256_lbf, Ki=0_ft∗lbf, Kf=12140.9961_ft∗lbf, W=12140.9961_ft∗lbf, Pavg=2.2075_hp.