The document discusses motion and force, covering distance, time, speed, and forces. Chapter Twelve focuses on distance, time, and speed, defining key terms like speed, velocity, constant velocity, and average speed. It explains how scientists describe motion using measurements of distance, time, and speed, and how these values are related through equations.
5. 12.2 Speed Speed is the most common measurement used to describe the motion of objects . Once you know an object’s speed, you can figure out how far it can go in a certain amount of time. You can also predict how long it will take to get somewhere.
6. 12.2 Speed The speed of a bicycle is the distance it travels divided by the time it takes.
8. 12.2 Constant Velocity A plane with a constant velocity of 600 km/h west moves in a straight line. (Its speed and direction remain the same.) A car going around a bend at a constant 30 mph has a constant speed , but its velocity is not constant. (Note the change in direction.)
9. 12.2 Average Speed The speed found by dividing the total distance by the total time is the average speed .
10. 12.2 Relationships between distance, speed and time An equation can be used to calculate speed, distance, or time if two of the three values are known.
12. Activity Speed is how fast something moves in relation to a reference point without regard to the direction. In this activity you and a partner will each calculate your average speed in different units. How Fast are You?