AP Physics 1 - Basic Vocab + Equations

Swaney my goat

Position

The location of something, (x, y, etc…)

initial position

The position of where an object starts; x_i

final position

the position where the same object ends up; x_f

distance (d)

total length of the path taken by an object; never negative

displacement

change in (total) position with the direction of change;
Δx = x_f- x_i (direction)

speed

• How fast an object travels

• Never negative

  • SI units = m/s

Instantaneous speed

How fast an object is going at a specific moment in time

Average speed

• how fast, on average, an object moves during a moment in time

• V_average = d_total / t_total

Constant Speed

When the speed of an object is always the same/unchanging

v = d / t

Velocity

• Speed + Direction; How fast somethign is traveling and what direction it is traveling

• Uses DISPLACEMENT

  • Not distance

Acceleration

How quickly an object’s velocity is changing; Acceleration = a
SI units = (m/s) / s = m/s²

Constant Acceleration (EQUATIONS)

• v_f = v_i + at

• d = ½ (v_i + v_t) t

• d = v_it + ½ at²

• v_f² = v_i² + 2ad

freefall

When the only force on a (falling) object is gravity; air resistance is ignored
A= 9.8 m/s²