MOTION

Main Idea: Motion Position and Speed

Learning Goals Explain the meaning of motion. Describe an object’s position. Write the speed formula.

Position The origin is the place where position equals 0. The position of this car at 50 cm describes where the car is relative to the origin. Position is a variable given relative to an origin.

Position Position and distance are similar but not the same. If the car moves a distance of 20 cm to the right, its new position will be 70 cm from its origin. Distance = 20 cm New position

Position and Speed The variable speed describes how quickly something moves. To calculate the speed of a moving object divide the distance it moves by the time it takes to move.

Formula Triangle ÷ ×

Speed The units for speed are distance units over time units. This table shows different units commonly used for speed.

Average speed When you divide the total distance of a trip by the time taken you get the average speed. On this driving trip around Chicago, the car traveled and average of 100 km/h.

Constant Speed Constant speed means the speed stays the same.

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