## 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`