We now know that unbalanced forces can change motion
Recognizing MotionTextbook pg 17-18 When is an object in motion? Are you or your book moving Compared to the floor? Compared to the sun? What is a reference point? What do we assume about a reference point? For the bus example, why do you think you are moving backward?
Recognizing Motion ANSWERSTextbook pg 17-18 When is an object in motion? When it’s distance from another object is changing Are you or your book moving? Compared to the floor? NO Compared to the sun? YES
What is a reference point?
A place or object used for comparison
What do we assume about a reference point?
It is stationary
Recognizing Motion ANSWERSTextbook pg 17-18 For the bus example, why do you think you are moving backward? Your reference point (the other bus) wasn’t stationary You Reference point
Now we are going to look at ways to describe and measure motion SPEED
How do we describe SPEED? HOW FAST SOMETHING GOES
How do we CALCULATE SPEED? How we describe the speed of a CAR: Miles per hour (MPH) OR Kilometers per hour (km/h) What does the miles or kilometers measure? They are units for distance What does the hour measure? It is a unit for time What does the “per” or “/” mean in math? division
Measuring Motion SPEED =RATE that an object moves Distance (D) Rate (speed) = Time (T)
DISTANCE Length between two places Distance = rate (speed) x time D= RT “Dirt”