Speed
This term describes speed at a given moment in time.
Instantaneous speed.
How do you calculate acceleration?
Final speed- start speed
___________________
Total Time
How does velocity differ from speed?
Velocity must include a direction. Other than that they are very similar.
Draw an example of a distance time graph where a car has stopped.
The line should be horizontal
What are the three ways that velocity changes?
Speed up
Slow Down
Change Direction
What does negative acceleration tell us?
The object is slowing down.
Draw an example of a graph where car that is stopped on a speed time graph.
The line should be completely flat on the bottom. No upward movement.
Draw an example of acceleration on a distance time graph.
The line should be curved and moving up to the right.
Marcy rides her bike across town 25 blocks. It takes her 15 minutes to get to her destination. What is her speed? Show your work and include labels!
Distance / Time
25 blocks/15 min=1.67 blocks/min (approx)
A rocket traveling back from the moon is approaching earth. Over a time of 110 seconds, it's speed goes form 300 m/s to 56 m/s. Calculate the acceleration. Include work and labels.
56 m/s - 300 m/s
______________
110 seconds
= -2.22 m/s^2 (must have ^2 and negative for points)
Draw an example of a speed time graph where the car is accelerating.
the line should be moving up at a diagonal slant to the right.
Draw a distance time graph where the car is returning to the start point.
Line is moving down to the bottom line.
Holly drives a distance of 100 miles at a speed of 67 mph. How long did it take her to reach her destination? Must include labels and show work!
Distance/speed
100 miles / 67 mph= 1.49 hours
Jeremy is merging on to the highway. His speed is 6 m/s after he has been driving for 10 seconds. At 15 seconds, his speed is 9 m/s. Calculate his speed. You must show the formula calculation to get credit and have correct labels.
9 m/s-6 m/s
__________
5 seconds
===0.6 m/s^2
If you do not have the ^2, it is not correct
How is constant speed shown on a speed time graph?
horizontal line
How is constant speed shown on a distance time graph
Straight diagonal line
James moved at a speed of 5 m/s on his scooter. It took him 89 seconds to reach his destination. What distance did he travel? Labels and work must be present to receive points.
Speed x Time
5 m/s x 89 s = 445 meters
Gene is traveling to Wentzville. 26 minutes into his trip, his speed is 25 m/s. By the time he reaches 29 min into this trip he has slowed to a complete stop. What is his acceleration? Be sure to include labels and work. (Hint: you may need to convert your min to seconds)
0 m/s -25 m/s
____________
3 min = (180 seconds)
= -0.14 m/s^2 (approx- must include negative and labels)