Question how we determine motion in an object. Demo with a small model car moving across the table and elicit that motion is relative to a stationary object. State that all motion is relative to a "stationary" object, even the Earth. State that when an object is moving it's position relative to a fixed point is changing. Unless otherwise stated, speed is relative to the Earth's surface. explain that the formula for determining speed involves distance and time. Discuss the difference between instantaneous speed and average speed, using examples. Elicit the difference between speed and velocity. Define velocity in terms of magnitude and direction.