1. Lesson 74: Measuring Speed

2. Vocabulary distance The length measured between two points
error Unavoidable variations between a measurement and the true
value of a quantity that occur when measurements cannot be
made with greater accuracy.
rate A ratio of two different kinds of measurement. Speed, the ratio of distance to time, is an example.
speed The rate at which an object moves, equal to the distance
traveled per time interval.
time interval The time between two events.
velocity The velocity of an object includes both its speed and its direction.

11. Why do you think speeding is a factor in about 20% of fatal car accidents?