AP Physics 1 Units

Displacement (x)

meters (m)

Mass (m)

kilograms (kg)

Time or Period (t or T)

seconds (s)

Velocity (v)

m/s

Acceleration (a)

m/s²

Force (F)

Newton (N); 1 N = kg m/s²

Coefficient of friction

unitless

Momentum (p)

kg m/s or Ns

Impulse (J)

kg m/s or Ns

Energy (all types including work) (K, U, W, etc)

joules (J); 1 J = 1 Nm = 1 kgm²/s²

Spring constant (k)

N/m = kg/s²

Power (P)

Watts (W); 1 W = 1 J/s = kgm²/s³

Angular Displacement

radians; rads

Angular Speed or Velocity or Frequency

radians per second; rad/s

Angular Acceleration

rad/s²

Rotational Inertia or Moment of Inertia (I)

kg m²

Angular Momentum (L)

kg m²/s

Torque

Nm = kgm²/s²

Frequency (f)

Hertz (hz); 1 Hz = 1/s

Volume (V)

m³

Area (A)

m²

Density (p)

kg/m³

Pressure (P)

Pascale (Pa) = N/m³

Volume Flow Rate (Q)

m³/s

Fab 5

v = vo + at

x = vot + ½ at²

v² = vo² + 2x

x = ½ (vo + v)t

x = v-t - ½ a²

Newton’s Second Law

F=ma

Force of Friction

F= uN

Gravitational Force (between two objects)

Fg = Gm1m2/r²

Net Centripetal Force

Fc = mv²/r

Work

W = Fdcos

Power

P = W/t

Kinetic Energy (both translational and rotational)

translational: KE = ½ mv²

rotational: KE = ½ Iw²

Potential Energy (both gravitational and elastic)

gravitational: Ug = mgh

elastic: Ue = ½ kx²

Total Mechanical Energy

TME = KE + PE

TME = ½ mv² + mgh

Work-Energy Theorem

Wnet = KE = KEf -KEi

Conservation of Energy

Ko + Po = Kf + Pf

Conservation of Total Mechanical Energy

KEfo+ PEo = KEf + PEf

Impulse-Momentum Theorem

J = (Delta)p = F (delta)t

Conservation of Momentum

elastic: m1v1o + m2v2o = m1v1f + m2v2f

perfectly inelastic: m1v1o + m2v2 = (m1 + m2)vf

Bridge Equations

s = r (theta)

v= rw

a = ra

Moment of Inertia for a point mass

I = mr²

multiple particles: I = m1r²1 + m2r²2

Individual Torque

t = rFsin(theta)

t = rF

Newton’s Second for rotation

tnet = Ia

Conservation of Angular Momentum

L = lw

Hooke’s Law

F = kx

Period of a spring and pendulum

spring: T= 2pi (square root) m/k

pendulum: T = 2pi (square root) L/g

General Wave Function (for sine and cosine)

y = Asin(Bx - C) + D

y = Acos(Bx - C) + D

Max Velocity and Acceleration of a SHM

Vmax = Aw

Amax = Aw²

Pressure

P = F/A

Pascale’s Principle

F1/A1 = F2/A2

Bernoulli’s Equation

P1 + pgh1 + ½ p(v1)² = P2 + pgh2 + ½ p(v2)²

Continuity Equation

A1v1 = A2v2

Buoyant Force

Fb = pVg

Q = vA