physical_week 1.notebook
October 31, 2013
http://youtu.be/DRb5PSxJerM
Road Race 1
Kilometers
Moon‐ a change in posion based on the reference point
place or object used for comparison to determine if something is in motion
To know if something moved you need to know:
‐starng point Distance ‐ending point
Feb 20­7:04 AM
Witch Math
How much farther?
Bat Math
Oct 28­8:44 AM
Final Positions
Initial Positions
Which went farther?
Why could we not accurately say which one
got there first?
What information do we need to know to
find out?
Which reached the desnaon first?
How do you know?
Oct 28­10:32 AM
Nov 30­10:57 AM
1
physical_week 1.notebook
October 31, 2013
`
What two measurements have we been discussing?
COPY in notebook:
So how do we calculate speed?
Nov 30­10:59 AM
Nov 30­10:24 AM
Let's make this information USEFUL to you....
2 Types of Speed
Constant Speed­ when an object moves at the same speed at all times
Examples:
D
S =
T
Average Speed­ the total distance that an object travels divided by the
total time it took to travel that distance • Average walking speed: 1.4 m/s
• Distance from music room to trojan academy: 72.5 meters
• How many seconds do you ACTUALLY need?
Examples:
Oct 28­12:04 PM
Oct 28­12:18 PM
2
physical_week 1.notebook
October 31, 2013
Copy into notebook:
D
Speed equals distance divided by time.
What if we add a direction to our speed?
S = T
Distance equals speed times time.
D= S x T
D
Time equals distance divided by speed
T = S
D
S T
Oct 31­7:40 AM
Oct 31­7:33 AM
Let's do a few more examples unrelated to us. What is the velocity of a car that travels a distance of 100 miles in 3 hours westward? D
S = If we are traveling 60miles per hour to Gatlinburg which is 240 miles away, how long will it take to get to Gatlinburg assuming we can drive straight there and there are no traffic D
delays?
S = T
T
D= S x T
D= S x T
D
T = D
S
T = S
Oct 28­10:21 PM
Oct 28­10:25 PM
3
physical_week 1.notebook
October 31, 2013
Mike hit a long fly ball to the left field. The left fielder picked up the ball and threw it 125 feet to the third baseman. The ball was in the air for 4 seconds. Then the third baseman relayed the ball to the catcher to make the play at home plate. Home plate was
97 feet away and the ball was in the air for another 3 seconds. What was the average speed of the ball?
D
S = T
D= S x T
D
T = S
Oct 28­10:27 PM
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