Unit 11 Motion

Position: It is the location of an object in relation to a nearby object or place. Ex. The ball is at different positions in this picture.

reference point: An idea, fact, or event that you already know, that helps you understand or make a judgement about another situation

motion: The act or process or moving or being moved. It is the change in position.

You know something is moving if its position changes against the background. The background is called the frame of reference.

By using your frame of reference can you determine which picture is 1st, 2nd and last?

Speed tells you how the position of an object changes during a certain amount of time. You can measure time in hours, minutes or seconds.

To find an object's speed, you divided how far it goes by the time it takes to get there. Ex. You walk 30 meters in 15 seconds then you speed is 2m/second. speed = distance / time

Velocity is the speed of an object in a particular direction. So velocity tells you how fast an object is moving and in what direction. Ex. The velocity is 60 km/h to the south.

Look at the picture of the turtle, cat and rabbit at the top of the page. You will use speed = distance / time

Force can change an object's speed or direction. Like pushing or pulling. Gravity is a form of force. Friction is another form of force.

Acceleration: is any change in velocity. Remember velocity tells both speed and direction of motion. So matter accelerates if it speeds up, slows down or changes direction.

Acceleration of any kind is caused by forces. Forces can push or pull on matter from all directions. If a force pushing against an object in one direction is greater than a force pushing in the opposite direction, the object will accelerate.