PowerPoint Slide show adapted from PowerPoint Slide show adapted from Mrs. Skinners ClassMrs. Skinners Class

http://sciencewithskinner.com/http://sciencewithskinner.com/index.htmindex.htm

Describing and Measuring MotionDescribing and Measuring MotionHow do you recognize motion?How do you recognize motion?

An object is in An object is in motionmotion when its when its distancedistance from from another object is another object is changingchanging

What is a reference point?What is a reference point?

An An objectobject is in motion if it is in motion if it changes changes positionposition relative to relative to a a referencereference point point

How do scientists calculate How do scientists calculate speed?speed?

Speed – the Speed – the distancedistance the the object travels in one unit of object travels in one unit of timetime

Speed = Speed = distancedistance

timetime

What is constant speed?What is constant speed?

If the If the speedspeed of of an object does an object does notnot change, change, the object is the object is traveling at a traveling at a constant constant speedspeed

What is average speed?What is average speed?Most objects do not travel at constant Most objects do not travel at constant

speedspeed

To find average speed To find average speed dividedivide the total the total distancedistance by the total by the total timetime

Avgerage Speed = Avgerage Speed = distance2-distance2-distance1distance1

time2-time1time2-time1

What is Velocity?What is Velocity?SpeedSpeed in a given in a given

directiondirectionWhen you know the When you know the speedspeed

and and directiondirection of an of an object’s motion, you know object’s motion, you know the the velocityvelocity of the object of the object

Example 15 km/hour Example 15 km/hour westwardwestward

How do you graph motion?How do you graph motion?

You can show the You can show the motionmotion of an object of an object on a on a lineline graph in graph in which you plot which you plot distancedistance against against timetime

TimeTime is along the x- is along the x-axis and axis and distancedistance on on the y-axisthe y-axis

How do you interpret motion How do you interpret motion graphs?graphs?

A A straightstraight line indicates line indicates a a constantconstant speed speed

The The steepnesssteepness depends depends on how quickly or slowly on how quickly or slowly the object is moving the object is moving The faster the motion The faster the motion

the the steepersteeper the slope the slope

What is Acceleration?What is Acceleration?

The The raterate at which at which velocityvelocity changes changes

In science, In science, acceleration refers acceleration refers to:to:increasingincreasing speed speeddecreasingdecreasing speed speedchanging changing directiondirection

How do you calculate How do you calculate acceleration?acceleration?

To determine the acceleration rate To determine the acceleration rate of an object, you must calculate of an object, you must calculate the the changechange in velocity during each in velocity during each unit of unit of timetime

Acceleration = Acceleration = Final velocity – Initial Final velocity – Initial velocityvelocity

TimeTime