Experiment Questions:

How does the Position/Distance vs. Time graph explain the speed of an object quantitatively? How does the acceleration of an object affect the slope of the line in a speed/velocity vs. time graph?

 Vocabulary:

• Speed:
  • The rate at which an object moves
  • Speed only changes when an object speeds up or slows down
    • Speed = Distance ÷ Time
• Velocity:
  • An objects speed in a specific direction
  • Velocity changes when an object speeds up, slows down, or moves in a different direction
• Acceleration:
  • the rate at which velocity changes

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Part 1: Constant Velocity (air puck experiment)

Finding the velocity at each meter: By finding the slope of the line from the Position/Distance vs. Time graph

Slope = Rise ÷ Run

Slope = (y₂- y₁) ÷ (x₂- x₁)

 

Use data from the air puck (Position vs. Time): Constant Speed

1. First, find the "Rise" which in this case is the "DISTANCE" between each tape mark.  SHOW ALL WORK in your science notebook!
2. Second, find the "Run" which in this case is the "TIME" it takes for the air puck to travel to each tape mark. SHOW ALL WORK in your science notebook!

 

Now, calculate the speed and enter it in the table above. You may use a calculator. Round to the nearest hundredth. Show the formula you used below:

 

Velocity = Rise÷Run At Meter 0:   =  0 m/s

Velocity = Rise÷Run From 0 - 1 meter:   = 1.61 m/s

Velocity = Rise÷Run From 1 - 2 meters:   = 1.61 m/s

Velocity = Rise÷Run From 2 - 3 meters:   = 1.61 m/s

Velocity =Rise÷Run from 3 - 4 meters:   = 1.61 m/s

 

Now Calculate the AVERAGE SPEED of the air puck from 0 m to 4 m.

Average Speed = Total Distance ÷ Total Time   4m ÷  2.48s   = 1.61 m/s

 

Velocity vs. Time Data Table (constant speed)

Part 2: Increasing Velocity (metal ball with ramp experiment)

Finding the velocity at each meter: By finding the slope of the line from the Position/Distance vs. Time graph

Slope = Rise / Run

Slope = (y₂- y₁) ÷ (x₂- x₁)

Use data from the ramp and metal ball (Position vs. Time): Speeding Up

1. First, find the "Rise" which in this case is the "DISTANCE" between each tape mark.  SHOW ALL WORK in your science notebook!
2. Second, find the "Run" which in this case is the "TIME" it takes for the air puck to travel to each tape mark. SHOW ALL WORK in your science notebook!

 

Now, calculate the speed and enter it in the table above. You may use a calculator. Round to the nearest hundredth. Show the formula you used below:

 

Velocity = Rise÷Run At Meter 0:     =  0 m/s

Velocity = Rise÷Run From 0 - 0.75 meter:   = 0.56 m/s

Velocity = Rise÷Run From 0.75 - 1.5 meters:   = 1.12 m/s

Velocity = Rise÷Run From 1.5 - 2.25 meters:   = 1.25 m/s

Velocity =Rise÷Run from 2.25 - 3 meters:   = 1.88 m/s

Calculate the AVERAGE SPEED of the metal ball from 0 m to 3 m.

Average Speed = Total Distance ÷ Total Time   3m ÷  3.06s   = 0.98m/s

 

Velocity vs. Time Data Table (Speeding Up)

Avg. Time (sec)	Velocity (m/s)
0	0
1.33	0.56
2	1.12
2.6	1.25
3.06	1.88

 

Qualitatively explain what you notice about the graph:

• Positive slope

 

Part 3: Decreasing Velocity (metal ball on floor experiment)

Finding the velocity at each meter: By finding the slope of the line from the Position/Distance vs. Time graph

Slope = Rise / Run

Slope = (y₂- y₁) ÷ (x₂- x₁)

Use data from the toy car (Position vs. Time): Slowing Down

Insert Decreasing Speed Data Table Here	Insert Position vs. Time (decreasing speed) Graph Here
Avg. Time (sec) Distance (m) 0 0 1.0 1 2.15 2 3.47 3 5.12 4

1. First, find the "Rise" which in this case is the "DISTANCE" between each tape mark.  SHOW ALL WORK in your science notebook!
2. Second, find the "Run" which in this case is the "TIME" it takes for the air puck to travel to each tape mark. SHOW ALL WORK in your science notebook!

 

Now, calculate the speed and enter it in the table above. You may use a calculator. Round to the nearest hundredth. Show the formula you used below:

 

Velocity = Rise÷Run At Meter 0:   =  0 m/s

Velocity = Rise÷Run From 0 - 1 meter:   = 1 m/s

Velocity = Rise÷Run From 1 - 2 meters:   = 0.87 m/s

Velocity = Rise÷Run From 2 - 3 meters:   = 0.76 m/s

Velocity =Rise÷Run from 3 - 4 meters:   = 0.60 m/s

 

Calculate the AVERAGE Speed of the car from 0 m to 4 m.

Average Speed = Total Distance ÷ Total Time   4 ÷  5.12   =0.78 m/s

 

Velocity vs. Time Data Table (Slowing Down)

Avg. Time (sec)	Velocity (m/s)
0	0
1.0	1
2.15	0.87
3.47	0.76
5.12	0.61

 

Qualitatively explain what you notice about the graph:

• Negative slope

 

Part 4: Analyzing Speed vs. Time Graph

Time Range	Is the car Accelerating, Decelerating or not Accelerating?	Is the slope Positive, Negative, or Zero Slope?
0 to 1 sec	Accelerating	Positive slope
1 to 2 sec	Not Accelerating	Zero slope
2 to 3 sec	Accelerating	Positive slope
3 to 6 sec	Decelerating	Negative slope

Time Range	Is the car Accelerating, Decelerating or not Accelerating?	Is the slope Positive, Negative, or Zero Slope?
0 to 5 hours	Accelerating	Positive slope
5 to 10 hours	Accelerating	Positive slope
10 to 15 hours	Not accelerating	Zero slope
15 to 20 hours	Decelerating	Negative slope
20 to 25 hours	Accelerating	Positive slope
25 to 30 hours	Decelerating	Negative slope

Part 5: Calculating Average Speed

• Speed = Distance ÷ Time

• Show ALL of your work!!

1.    A car travels 300 miles in 6 hours.  What is the average speed of the car?

Speed = 300m ÷ 6h

Speed = 50 mph

2.    You ride your bike to your friend’s house.  You know that he lives 2500 meters away because you were bored one day and measured it.  It took you 10 minutes to get there.  What was your average speed on the bike?

Speed = 2500m ÷ 10min.

Speed= 250 meters per hour

3.    You are at home and dying for a slurpee so you walk to 7-11 to get one.  It’s 2000 feet away.  After walking 4 minutes you meet up with friends and talk for 3 minutes.  Your friends then join you and it takes you another 5 minutes to get to 7-11.  What is your average speed for you to go from your house to 7-11?

Speed = 2000ft. ÷ 9min.

Speed = 222.22 ft/min

4. Fill in the data table

• You will need to rearrange the equation Speed = Distance / Time to find the missing information
• SHOW ALL WORK IN YOUR SCIENCE NOTEBOOK!

Part 6: Summary