Mot ion & Speed and Velocity & Acceleration

Motion When an object moves it is considered to be in motion. We define motion as the change in an objects position. The faster an object can move the faster its position can change.

Position The location of an object at any moment of time is defined as the objects position. When an object moves its position it is said to be in motion.

Speed Speed has two important components. The first is “time” and the second is “motion.” We define motion as the change in an objects position. Speed is defined how fast an object changes its position over time.

Instantaneous Speed The speedometer in a car tells us the speed at any moment in time when we are driving. Instantaneous speed is the speed of an object at any single moment in time. Speed is an important part of keeping an airplane in the sky. The amount of air flowing over the wings keep the plane in the air, but when the amount of air decreases the plane will stall.

Average Speed The average speed of an object is the distance an object travels divided by the time the object traveled. An example would be a plane traveling 2500 miles in 5 hours averages 500 miles per hour during its flight time. What is average speed of an arrow in the air which travels 75 yards in three seconds. Compare the average speed in feet per second.

Calculating Speed DRT formula Distance = Rate X Time Rate = Distance/Time Time = Distance/Rate

Velocity and Acceleration Understanding how objects move through the environment

Velocity Velocity is a term which is used to describe both speed and direction An example would be a plane flying at 500 miles an hour going due North. Notice there is both a direction and a speed for the movement of the plane. Like speed, velocity can change.

Acceleration Acceleration is the rate of change of velocity Because velocity includes both speed and direction, if either changes the velocity will change. Acceleration can occur through a change in speed or a change in direction Acceleration of an object traveling in a straight line is just the rate of change of speed.

Positive Acceleration The velocity and acceleration of an object being in the same direction. An object is speeding up.

Negative Acceleration The velocity and acceleration of an object being in opposite direction. An object is slowing down.

Calculating Acceleration Acceleration is determined by dividing the change in velocity by a duration of time. Acceleration accounts for the starting and final velocity of an object. A = velocity (final) – velocity (initial) Duration time