## Velocity and Speed

The average velocity v_(x,avg) of a particle is defined as the particle’s displacement ∆x divided by the time interval ∆t during which that displacement occurs: v_(x,avg)=(∆x)/(∆t) The average speed v_(avg) of a particle, a scalar quantity, is defined as the total distance d traveled divided by the total time interval required to travel that distance: v_(avg)=d/(∆t) From Example 1: Average velocity of the car from A to F: ∆x = -53 m - 30 m = -83 m ∆t = 50s-0s = 50s v_(x,avg)=(∆x)/(∆t)=(-83m)/(50s) = -1.7 m//s Average speed of the car from A to F: d_(a->f) = 127 m ∆t = 50s-0s = 50s v_(avg)=d_(a->f)/(∆t)=(127m)/(50s) = 2.5 m//s