Motion in One Dimension Changes in Velocity

Acceleration Acceleration – rate of change in velocity Positive acceleration usually means speeding up Negative acceleration usually means slowing down Calculated using the following formula average acceleration = (final velocity – initial velocity) time interval aavg=Δv/Δt

Acceleration Measured in meters per second squared (m/s2) Has both magnitude and direction a=35 m/s2 northwest If acceleration equals zero, velocity is constant

Velocity-Time Graphs If you graph velocity versus time Slope equals acceleration Positive slope – usually means positive acceleration Can mean negative acceleration in the negative direction Negative slope – usually means negative acceleration Can mean positive acceleration in the negative direction No slope (flat line) – no acceleration Velocity is constant Straight line – constant acceleration

Velocity-Time Graphs

Velocity-Time Graphs

Motion With Constant Acceleration For an object with constant acceleration Can calculate average velocity Average velocity = (initial velocity + final velocity) 2 vavg= Σv/2 Displacement = 1/2 (initial velocity + final velocity) (time interval) Δx =1/2Σv Δt

Motion With Constant Acceleration

Motion With Constant Acceleration

Motion With Constant Acceleration