in class work packet unit 1. one dimensional kinematics … physics 1/assignments... · lab...

IN CLASS WORK PACKET Unit 1. One Dimensional Kinematics AP Physics 1 Name: ___________________________

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Date In Class Homework to completed that evening

(before coming to next class period)

8/16 Tues (A) Intro to AP Physics 1

Pre-assessment

Watch: 1D Kinematics video 1.

Representing Motion Verbally

8/17 Wed (A) Discuss video 1 and positives and

negatives in physics

Watch 1D Kinematics video 2.

Representing Motion Visually Part I

8/18 Thur (B)

8/19 Fri (C)

Graphing Motion Discussion and

Interpreting x-t and v-t graphs

Watch 1D Kinematics video 3.

Representing Motion Visually Part II

8/22 Mon (A) Graphing Motion Discussion/Activity

8/23 Tue (B)

8/24 Wed (C)

Cart and Buggy Lab

***need lab notebook Study for graphing quiz

8/25 Thur (B)

8/26 Fri (C)

Quiz over graphing motion and

lab discussion/work on packet

Watch 1D Kinematics video 4 Kinematic

equations

8/29 Mon (A)

LSM Discuss Kinematic equations Watch 1D Kinematics video 5: Free Fall

8/30 Tues (B)

8/31 Wed (C)

Discuss Free Fall, air resistance and

Activity

9/1 Thur (B)

9/2 Fri (C)

In class work on packet and review for

test

9/5 Mon Labor Day (NO School) Study for 1D test

9/6 Tue (B)

9/7 Wed (C) 1 D Kinematic Test

Watch 2D Video 1. Vector addition and

relative motion


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In Class Practice for Video 1. 1. A moth flies a distance of 3 m in only one-third of a second.

a. What does the ratio 3/(1/3) tell you about the moths motion? Explain.

b. How far would the moth fly in one-tenth of a second?

c. How long does it take for the moth to fly 4 m?

2. Eight possible signs of combination for the instantaneous position, velocity and acceleration of an object moving in one dimension are given in the table. Above the table is a coordinate axis that shows the origin, marked 0. The positive direction is to the right. The three columns on the right-hand side of the table are to describe the location of the object (either left or right of the origin), the direction of the motion of the object (either toward or away from the origin), and what is happening to the speed of the object (either speeding up or slowing down at the given instant). The appropriate descriptions for the first case are shown. Complete the table for the object’s location and direction of motion relative to the origin and how its speed is changing.

Position Velocity Acceleration Position (left or

right) Direction (Toward

or away) Rate (Speeding up or

slowing down)

A + + + Right Away Speeding up

B + + -

C + - +

D + - -

E - + +

F - + -

G - - +

H - - -


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3. A student walks along a trail with a constant speed of 8 km per hour for 1 hour and then turns around and walks

back to her starting point at a constant speed of 6 km per hour. She contents:

“My average speed was about 6.9 km per hour since I walked a total of 16 km in two and one-third hours.” What, if anything, is wrong with this statement? If something is wrong, identify it and explain how to correct it. If this statement is correct, explain why.

4. A student contents: “If I climb up a mountain at 1 mile per hour for 2 hours and then turn around and climb back

down at 3 miles per hour, then my average speed will be 2 miles per hour.”

What, if anything, is wrong with this statement? If something is wrong, identify it and explain how to correct it.

If this statement is correct, explain why.

In Class Practice Video 2. Motion diagrams and graphs of motion

5. Draw a motion diagram for the following scenarios. Use the particle model to represent the object as a particle

and use 6-8 dots for the diagram.

a. A car accelerates forward from a stop sign. It eventually reaches as steady speed of 45 mph.

b. An elevator starts from rest at the 100th floor of the Empire state building and descends, with no stops, until

coming to rest on the drown floor. (Draw this vertically since the motion is vertical.

c. A skier stars from rest at the top of a 30° snow-covered slope and steadily speeds up as she skies to the

bottom. (orient your diagram as seen from the side, so make on an incline. Label the 30° angle.)


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6. In each of the cases below, a sphere is moving from left to right next to a tape marked in meters. A photograph is

taken every second, and the location of the sphere is recorded. The first sphere is located at t=0 s. The total time

intervals shown are not the same for all spheres.

a. Rank the magnitude of the displacement over the first 2 seconds from greatest to least. And explain your

reasoning.

b. Rank the magnitude of the displacement over the first 3 seconds from greatest to least. And explain your

reasoning.

c. Rank the magnitude of the average velocity over the first 3 seconds from greatest to least. And explain your

reasoning.

7. Sketch a position vs. time graph for the following motions. Note: a sketched graph is hand-drawn, rather than laid

out with a ruler. Even so, a sketch must be neat, accurate

and include axis labels.

a. A Pokémon Go player walks up Eastgate lane and stops

at the sunflower painted utility box for a gym battle.

After successfully winning the battle and installing a

Pokémon, they continue to the Pokestop at the

fountain. Assume that all motion is along a straight

line.

b. A student walks slowly to the bus stop, realized he

forgot his physics packet and quickly walks home to get

it.

c. The quarterback drops back 10 yards from the line of

scrimmage, and then throws a pass 20 yards to a

reciever, who catches it and sprints 20 yards to the

goal. Draw your graph for the football. Think carefully

about the slopes of your lines.


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8. The figure shows a position vs. time graph for the motion of objects A and B that are moving along the same axis.

a. At the instant t=1 s, is the speed of A greater than, less than, or equal to the speed of

B? Explain.

b. Do objects A and B ever have the same speed? If so at what time or times? Explain.

c. Do objects A and B ever have the same position? If so at what time or times? Explain.

9. The positon vs. time graph shown to the right shows the

position of an object moving in a straight line for 12 seconds.

a. What is the position of the object at 2 s, 6 s, and 10 s after

the start of motion?

i. 2 s =

ii. 6 s =

iii. 10 s =

b. What is the objects velocity?

i. during the first 4 s of motion?

ii. during the interval from t = 4 s to t = 6 s?

iii. during the four seconds from t= 6 s to t = 10 s?

iv. during the final two seconds from t = 10 s to t = 12 s?

c. Using this data construct a velocity vs. time graph on the

axis to the right. Be sure to label your axis and make an

appropriate scale.


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10. The figure shows a position vs. time graph for a moving object. At which of the

lettered point or points (and why?)

a. Is the object moving the slowest without being at rest?

b. Is the object moving the fastest?

c. Is the object at rest?

d. Does the object have constant nonzero velocity?

e. Is the object moving to the left?

11. If instead the graph in 10 above were a velocity vs. time graph, what would your answers be? (and why?)

a. Is the object moving the slowest without being at rest?

b. Is the object moving the fastest?

c. Is the object at rest?

d. Does the object have constant nonzero velocity?

e. Is the object moving to the left?

12. Below are six position vs. time graphs. For each, draw the corresponding velocity vs. time graph directly below it.

A vertical line drawn through both graphs should connect the velocity vx at time t with the position x at the same

time t. There are no numbers, but your graphs should correctly indicate the relative speeds.


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13. The figure shows six frames from the motion diagram of two moving cars, A and B. a. Draw both a position vs. time graph and a velocity vs. time

graph. Show both cars on each graph. Label them A and B.

b. Do the two cars ever have the same position at one instant of time? If so, in which frame number(s)? Draw a vertical line through your graphs of part a to indicate this instant of time.

c. Do the two cars ever have the same velocity at one instant of time? If so, between which two frames?

14. Two cars travel on the parallel lanes of a two-lane road. The cars’ motions are represented by the position versus time graph shown in the figure. Answer the questions using the times from the graph indicated by letters. a. At which of the times do the two cars pass each

other? How do you know?

b. Are the two cars traveling in the same direction

when they pass each other? Explain!

c. At which of the lettered times, if any, does car #1 momentarily stop? How do you know?

d. At which of the lettered times, if any, does car #2 momentarily stop? How do you know?

e. At which of the lettered times are the cars moving with nearly identical velocity? How do you know?


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In Class Practice video 3 15. The graphs below show the velocity versus time for boats traveling along a straight, narrow channel. The scales on

both axes are the same for all of these graphs, and the boats all start at the same origin. In each graph, a point is marked with a dot.

Indicate in the chart below if the position, velocity, and acceleration directions of the boat at the point indicated are in the positive (+), negative (-) or no direction (0).

Position Velocity Acceleration

A

B

C

D

E

F

16. A student is given the following acceleration vs. time graph for a

motorcyclist traveling along a straight, level stretch of road.

The student states: “This motorcyclist was slowing down during the period

up to 14 seconds because her acceleration was negative during this

period.”

What, if anything is wrong with this student’s contention? If something is wrong, identify it and explain how to

correct it. If it is correct, explain why.

Explain your reasoning:


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17. A student obtains a graph of an object’s velocity versus time and then draws the graph of acceleration vs. time for

the same time interval. What if anything, is wrong with the graph of acceleration vs. time? If something is wrong,

identify it and explain how to correct it. If the graph is correct, explain why.

18. A student obtains a graph of an object’s velocity versus time and then draws the graph of acceleration vs. time for

the same time interval. What if anything, is wrong with the graph of acceleration vs. time? If something is wrong,

identify it and explain how to correct it. If the graph is correct, explain why.

19. Below are three velocity vs. time graphs. For each, draw the corresponding acceleration vs. time graph.

20. Below are two velocity vs. time graphs. For each draw the corresponding position vs. time graph and write a

description of motion.


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21. Shown below are velocity vs. time graphs for toy robots that are traveling along a straight hallway. All graphs have

the same time and velocity scales.

a. Rank the magnitude of the displacements during these time intervals. Explain your reasoning.

b. Rank the distances traveled during these intervals. Explain your reasoning.

22. You are running in a race (I’m impressed!)

and we have decided to graph your

movement.

Zero to 90s: Let’s look at how you are

running in those first 90 seconds.

a. What is your average velocity during

this time period (0-90s)?

b. What is your instantaneous velocity at

60 seconds?

c. Are your answers to 1 and 2 the same or different? Why?

d. Are you accelerating?

90s to 150s Yikes! You ran too fast at the start and now you’re out of breath!

e. What is your distance during this time period?

f. What is your velocity during this time period?

g. What happened?


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150s to 240s

h. By looking at the graph are you moving _____faster or _____slower than you did in the first 90 s?

i. What is your velocity during this time period?

240s to 300s

j. What is your velocity in this period?

k. What does this mean (which way are you going?)

300s to 360s

l. How would you describe your motion during this time interval?

360s to 510s: You know that you have only one chance to still win the race… run as fast as you can!

m. What is your average velocity during this time period?

n. i. What is your instantaneous velocity at 420 s? ii. What is your instantaneous velocity at 480 s?

o. What do the differences in m & n represent? (what does a curved line on a position vs time graph

mean?)

p. Graph your velocity vs. time on the grid

to the right. Label your axis with proper

units and use an appropriate scale for

both time and velocity.


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q. In the table below properly identify the type of velocity you exhibited during the race

Time interval Constant or Changing +, -, zero Average Velocity (m/s) Ave. Acceleration (m/s2)

Zero to 90s

90s to 150s

150 to 240s

240 to 300s

300 to 360s

360 to 510s

23. The following graph describes the velocity

of an automobile as a function of time

a. What was the velocity of this car when t = 35 seconds? b. During which time interval/intervals was the car at rest? How do you know? c. During which interval/intervals was the car moving in reverse? How do you know? d. What was the displacement of this car between t = 0 and t = 10 seconds? e. What was the displacement of this car between t = 10 and t = 25 seconds? f. What was the displacement of this car between t = 25 and t = 40 seconds? g. What was the total displacement of this car between t = 0 and t = 110 seconds? h. What was the total distance traveled by this car between t = 0 and t = 110 seconds? (is it different from #7 and why?)


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i. Calculate the acceleration of the car and graph the data making sure to appropriately scale the graph:

Time (s)

Acceleration (m/s2)

5

20

35

50

60

90

In Class Practice for Video 4. Kinematic Equations: 24. For the problems below, i) draw a motion diagram of the situation, ii) make a table of all known and unknown

variables, iii) write the kinematic equation necessary to solve the problem iv) rearrange the equation to solve for

the unknown variable, v) only after these steps have been completed may you plug your numbers in a solve for

the unknown.

a. A car traveling at 30 m/s screeches to a halt, leaving 55-m-long skid marks. What was the cars acceleration

while breaking?

b. A bicyclist starts from rest and accelerates at 4 m/s2 for 3.0 s. The cyclist then travels for 20 s at a constant

speed. How far does the cyclist travel? (Note: there are 2 phases of motion so you will need two separate

tables/equations or more)

c. You are driving your car at 12 m/s when a deer jumps in front of y our car. What is the shortest stopping

distance for your car if your reaction time is 0.80s and your car brakes at 6.0 m/s2? (Note: there are 2 phases

of motion so you will need two separate tables/equations or more)


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25. A car is initially traveling with a constant velocity of 12 m/s as it moves down the highway. The car travels a distance of 175 m at this velocity.

a. How long will it take the car to travel the 175 m while moving at a constant 12 m/s?

b. After moving at 12 m/s for the time found in part a, the driver pushes her foot down farther on the gas pedal, accelerating at 1.5 m/s2 for 10 seconds.

i. How fast was the car moving after 10 seconds of accelerating?

ii. How far did the car move during this 10 second acceleration?

c. Just as the driver reaches the speed found in part c. above, she notices an accident has occurred farther down the road and she applies the brakes, coming to a complete stop after traveling an additional 50 meters.

i. What was the acceleration of the car while stopping?

ii. How long did it take for the car to stop?

d. Make accurate graphs of position vs. time and velocity vs. time on the axes below showing the motion of this car during this entire problem.


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26. Santa’s elves are building an experimental rocket powered sled. The rocket sled is mounted on wheels and

placed on a set of straight railroad tracks. At t=0 the rocket is ignited, causing a constant acceleration of

15m/s2 until t= 8s. From t= 8s to t= 20s the rocket travels at a constant velocity. At t= 20s the engine is shut

down and the brakes are applied.

a. What is the velocity of the sled at t=8s? b. How far does the sled travel during the first 8 seconds? c. How far does the sled travel from t=8s to t=20s? d. After the brakes are applied at t=20s the sled continues to move forward for 680 m. Calculate the acceleration while the brakes are applied. e. Calculate how long it takes the sled to come to a stop after the brakes are applied at t=20s. f. Graph the motion of the sled from t=0s until it comes to a stop.


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In Class Practice for Video 5. Free Fall 27. A rock this thrown (not dropped) straight down from a bridge into the river below.

a. Immediately after being released, is the magnitude of the rock’s acceleration greater than g, less than g,

or equal to g? Explain.

b. Immediately before hitting the water, is the magnitude of the rock’s acceleration greater than g, less than

g, or equal to g? Explain.

28. A ball is thrown straight up into the air. It reaches height h, and then falls back down to the ground. On the

axes below, graph the ball’s position, velocity, and acceleration from an instant after it leaves the thrower’s hand until an instant before it hits the ground. Indicate on your graphs the times during which the ball is moving upward, at its peak, and moving downward.

29. A ball is thrown straight upward and falls back to the same height. A student makes the graph

of speed of the ball as a function of time. Three students who are discussing this graph make

the following contentions:

Sammy: “I don’t think that this can be correct because the sign of the acceleration changes

on this graph, but the acceleration of the ball will be constant.”

Burt: “No, I think this is right because it is only showing what happens to the speed, which will decrease

to zero at the top and then increase as the ball falls. Since the slopes for both segments are the

same except for the sign that means the acceleration is constant.”

Kurt: “This graph makes sense to me because it shows the speed decreasing on the way up. But I

disagree with Burt, because I think this means the acceleration is also decreasing until the ball

gets to the top and stops. Then both the speed and acceleration increase as the ball falls down

again.”

With which, if any, of these three students do you agree?

Sammy_________ Burt______________ Kurt_____________ None of them________________

Explain your reasoning.


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30. A model rocket is launched straight up with constant acceleration a. It runs out of fuel at time t. Suppose you

need to determine the maximum height reached by the rocket. Assume air resistance is negligible.

a. Is the rocket at maximum height the instant it runs out of fuel? ____________

b. Is there anything other than gravity acting on the rocket after it runs out of fuel? ______________

c. What is the name of motion under the influence of only gravity? __________________________

d. Draw a pictorial representation for this problem in the

box to the right. You should have three identified

points in the motion: Launch, out of fuel, and maximum

height. Call these points 1, 2, and 3.

i. Using subscripts, define 11 quantities: y, vy, and t at

each of these three points, plus acceleration a1

connecting points 1 and 2 and acceleration a2

connecting points 2 and 3.

ii. 7 of these quantities are Knows; identify them and

specify their values. Some are 0. Others can be given

in terms of a, t and g, which are “known,” because

they are stated in the problem, even though you

don’t have numerical values for them. For example, t1

= t. Be careful with signs!

iii. Identify which one of the 4 unknown quantities

you’re are trying to find.

e. This is a two-part problem. Write two kinematic equations for the first part of the motion to determine-

again symbolically-the two unknown quantities at point 2.

f. Now write a kinematic equation for the second half of the motion that will allow you to find the desired

unknown that will answer the question. Just write the equation; don’t yet solve it.

g. Now, substitute what you learned in part e into your equation of part f, do the algebra to solve for the

unknown, and simplify the result as much as possible.

31. A ball is thrown upward so that it just barely reaches the top of a telephone pole and then falls back to the

ground. The time from the release of the ball until its return to the ground is measured to be 5.20 seconds.

What is the height of the telephone pole?


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32. A ball is thrown downward from the top of a building 122 meters tall with an initial speed of 38.0 m/s. What

will be the velocity of this ball as it reaches the ground?

33. You are standing on the top of a building which is 115 meters tall. You throw one ball upward at 35.0 m/s and

it lands on the ground some time later. You throw a second ball downward from the same building with a

velocity of 35.0 m/s and it also hits the ground at a later time. Which ball will be moving faster when each hits

the ground? Support your answer with calculations!

34. A ball is thrown upward with a speed of 38.0 m/s from the top of a building 240. meters tall;

a. What will be the velocity of this ball at the highest point?

b. How long will it take for this ball to reach the highest point?

c. How long will it take for this ball to reach the ground?

d. How long after the ball is thrown will the ball be found 265 meters above the ground?

e. What will be the velocity of this ball as it reaches the ground?

f. How high above the ground will the ball be when it reaches the highest point?

Suppose that instead of throwing this ball upward it is thrown downward with a speed of 38.0 m/s; g. How long will it take for the ball to reach the ground?

h. What will be the speed of the ball as it reaches the ground?

in class work packet unit 1. one dimensional kinematics … physics 1/assignments... · lab...

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