Acceleration

Acceleration tells how much an object’s speed changes in one second.

When an object speeds up, its acceleration is in the direction of motion.

When an object slows down, its acceleration is opposite the direction of motion.

Objects in free fall gain or lose 10 m/s of speed every second

Algebraic kinematics – You must follow these steps to solve an algebraic kinematics calculation.

1. Define a positive direction, i.e. the direction “away from the detector. Label that direction.
2. Indicate in words what portion of motion you are considering, e.g. “motion from launch to the peak of the flight.”
3. Fill out a chart, including signs and units, of the five kinematics variables:

vo [initial velocity]

vf [final velocity]

Δx [displacement]

a [acceleration]

t [time for the motion to happen]

1. If three of the five variables are known, the problem is solvable; use the kinematics equations to solve.

vf = vo + at

Δx = vot + ½at2

vf2 = vo2 + 2aΔx

A fourth equation may occasionally be useful:

Δx = ½t(vo + vf)