BCLN Science 10 - Rev. Sept/2014
Unit 9 ~ Learning Guide Name: ______________________________
Instructions:
Using a pencil, complete the following notes as you work through the related lessons. Show ALL
work as is explained in the lessons. You are required to have this package completed BEFORE
you write your unit test. Do your best and ask questions if you don’t understand anything!
Acceleration:
1.
The pool ball shown below was photographed 8 times at equal time intervals. Is the pool ball’s
motion uniform? How do you know? Sketch a d vs t and v vs t graph, showing the general
shape of each graph.
2. Make a sketch of what the pool ball’s photos would look like if it were accelerating (both
positively and negatively).
3. Acceleration is often a difficult term to understand. How could you best explain the acceleration
of a car (and how it’s different then velocity) to a non-physicist?
4. How can you recognize uniform motion on a d vs t graph?
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BCLN Science 10 - Rev. Sept/2014
5. What are common units for the following:
a. Displacement / Distance (provide 6 examples and circle the SI standard one):
b. Time (provide 3 and circle the SI standard one):
c. Velocity / Speed (provide 4 and circle the SI standard one):
d. Acceleration (provide 3 and circle the SI standard one):
6. A toboggan accelerates from rest at 1.1 m/s2. After 10 seconds, how fast is it going? Show the
equation used and all steps.
7. At the bottom of the hill, the toboggan moving 12 m/s forward accelerates at -0.50 m/s2 for 10 s.
What is the toboggan’s velocity at the end of the 10 s? Show the equation used and all steps.
8. How much time does it take a car travelling south at 12 m/s to increase its velocity to 26 m/s
south if it accelerates at 3.5 m/s2 south? Show the equation used and all steps.
9. The acceleration of a freely falling object (near Earth), when we assume no air resistance, is
__________ (remember units).
10. The assumption of no air resistance is never totally true, but is often close enough to make pretty
accurate calculations. Discuss cases where this is a really good assumption and when it isn’t.
11. A stone is dropped from a cliff. What is it's velocity after 1 second? After 2 seconds?
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BCLN Science 10 - Rev. Sept/2014
12. A ball is thrown straight up into the air at 14 m/s. How long does it take for the ball to slow down
to an upward velocity of 6.0 m/s? Show the equation used and all steps.
13. If you throw a rock up into the air, when is its velocity zero? What is the acceleration when the
velocity is zero?
14. A rock is thrown downwards with an initial velocity of 8.0 m/s. What is the velocity of the rock
after 1.5 s?
15. If a car is going 100 km/hr as it passes a bystander, then passes another bystander 20 seconds
later when it’s going 120 km/hr, what is the car’s average acceleration? Show all work as
demonstrated in the lessons.
16. You started to run at 10 km/h when you left your house and you arrived at school 30 minutes
later. Assuming that your average acceleration was 30 km/h2, how fast were you running when
you arrived?
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BCLN Science 10 - Rev. Sept/2014
17. As difficult as it is to visualize the changes in velocity, a good understanding of acceleration is
needed to master kinematics problems. Recognizing that acceleration can be positive, while
velocity is positive (and visa) is definitely brain exercise.
a. Object is speeding up (from still) in the positive direction. For example, a ball is placed on a
slanted ramp.
Velocity is positive / zero / negative and increasing / constant /decreasing.
Acceleration is positive / zero / negative.
b. Object is speeding up (from still) in the negative direction. For example, a ball is placed on a
ramp that is slanted towards the negative direction (eg. down to the left).
Velocity is positive / zero / negative and increasing / constant /decreasing.
Acceleration is positive / zero / negative.
c. Object is slowing down in the positive direction. For example, you push a ball up a slanted
ramp.
Velocity is positive / zero / negative and increasing / constant /decreasing.
Acceleration is positive / zero / negative.
d. Object is slowing down in the negative direction. For example, you push a ball up a ramp
that is slanted towards the negative direction (eg. down to the right).
Velocity is positive / zero / negative and increasing / constant /decreasing.
Acceleration is positive / zero / negative.
18. Review your results from the previous question to build general statements that are always true:
Acceleration is always in the opposite direction of ______________ if the object is slowing
down.
Acceleration is always in the same direction of ________________ if the object is speeding up.
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BCLN Science 10 - Rev. Sept/2014
Graphing with Acceleration:
1. What’s a tangent line and what is it used for? Sketch an example.
2. What is the slope of a v vs t graph for a free falling object? Why?
3. If wind resistance was included in the previous question, would the slope be bigger or
smaller? ______________________
4. Describe the Apollo 15 experiment involving the hammer and feather. Explain why this
doesn’t work on Earth.
5. What is the acceleration shown in the following graph?
6. Sketch d vs t and v vs t graphs for a stone that was dropped off a 30 m cliff. Just the
rough shape and highlights is good.
7. Sketch d vs t and v vs t graphs for a stone that was thrown upwards at 5 m/s. Just the
rough shape and highlights is good.
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BCLN Science 10 - Rev. Sept/2014
8. The motion of a race cart on a linear track is shown below.
a) When is the car at the starting
line?
b) When is the car sitting still?
c) When is the car going in the
negative direction?
d) What is the fastest speed logged? When does it happen?
9. Use both area and equation to determine the displacement traveled in the following graph.
10. Use both area and equation to determine the displacement traveled in the following graph.
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BCLN Science 10 - Rev. Sept/2014
11. Provide a description of a sample situation for each of the graphs below (make sure to
recognize each graph as d vs t, v vs t, or a vs t).
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BCLN Science 10 - Rev. Sept/2014
Unit 9 Learning Guide Answers:
Please note that some answers are directly from the online notes. Answers are given when
needed.
Acceleration:
1)
uniform-explain 4)linear-explain 5) m, s, m/s, m/s2 6)11m/s[downhill] 7)+7m/s 8)4s
9)-9.8m/s2 11)-9.8m/s,-19.6m/s 12)0.83s 13)top,-9.8m/s2 14)-23.7m/s[down] 15)0.28m/s2
16)25km/h or 6.9m/s 17)a)pos, inc, pos b) neg, dec, neg c) pos, dec, neg
18)velocity, velocity
Graphing with Acceleration:
2) -9.8m/s2-explain 3)smaller-explain 5)12.5m/s2
6)
7)
8)a)unknown b)0s,30s,55s c)15-40min d)60m/min 9)+50m 10)+50m
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d) neg, inc, pos