Motion Recognizing Describing and Measuring Motion Am I

Motion Recognizing, Describing, and Measuring Motion

Am I moving?

Recognizing Motion An object is in motion when its distance from another object is changing. n Whether an object is moving or not depends on your point of view. n

n Relative Motion A reference point is a place or object used for comparison to determine if something is in motion. n An object is in motion if it changes position relative to a reference point. n The reference point is stationary, or not moving.

Frame of Reference

Am I moving? My husband says we are moving. I say we are not. 1. Choose a partner. 2. Explain in words and pictures why both my husband I are correct. 3. Your work must include the following terms: • Point of reference • Point of view • Distance • Motion AC

Am I moving? My husband says we are moving. I say we are not. 1. Choose a side. 2. Explain in words and pictures why you are correct. 3. Your work must include the following terms: • Point of reference • Point of view • Distance • Motion

Measuring Motion Speed is the distance an object travels per unit of time. n If it takes you 1 hour to drive a total of 60 miles, then how fast were you going? n n n 60 mph (miles per hour) To calculate speed: n Divide the distance by the time

Average Speed Most objects do not move at constant speeds for very long. n Think about how many stops you have to make on your way to school each day. n To calculate average speed, is the total distance divided by the total time. n

Velocity n n Knowing the speed of an object will not tell you everything about its motion. Velocity is the SPEED & DIRECTION of and object. Velocity changes if either speed or direction changes. With storms, you need to know the velocity of its motion !

Graphing Motion

Acceleration is the rate at which velocity changes. n It refers to increasing speed , decreasing speed (deceleration), or changing direction. n

Calculating Acceleration To determine the acceleration of an object, you must calculate the change in velocity during each unit of time. n The formula for this is: n n Acceleration = Final velocity –Initial velocity/Time

Calculating Acceleration n Lets Try: n A car advertisement states that a certain car can accelerate from rest to 90 km/h in 9 seconds. Find the car’s average acceleration. n An bird accelerates from 15 m/s to 22 m/s in 4 seconds. What is the eagle’s average acceleration?