Transcript Document

Chapter 1 Clickers
Kinematics:
Motion
in One Dimension
Prepared by
Dedra Demaree,
Georgetown University
© 2014 Pearson Education, Inc.
The object represented by the following motion
diagram is:
a)
b)
c)
d)
Slowing down.
Moving to the right.
Moving with constant velocity.
Speeding up.
© 2014 Pearson Education, Inc.
The object represented by the following motion
diagram is:
a)
b)
c)
d)
Slowing down.
Moving to the right.
Moving with constant velocity.
Speeding up.
© 2014 Pearson Education, Inc.
What can we conclude about the motion of the two
objects represented by the following motion
diagrams?
a)
b)
c)
d)
Both objects are moving at constant speed.
Object 2 is moving more slowly than object 1.
The objects could be moving either left or right.
We can conclude all of the above.
© 2014 Pearson Education, Inc.
What can we conclude about the motion of the two
objects represented by the following motion
diagrams?
a)
b)
c)
d)
Both objects are moving at constant speed.
Object 2 is moving more slowly than object 1.
The objects could be moving either left or right.
We can conclude all of the above.
© 2014 Pearson Education, Inc.
Given the following motion diagram, what is the
direction of the change in the velocity vector?
a) The change in velocity vector is to the left.
b) The change in velocity vector is to the right.
c) The change in velocity vector is zero because the
velocity is constant.
d) It is impossible to determine the direction of the
change in velocity vector from the given
information.
© 2014 Pearson Education, Inc.
Given the following motion diagram, what is the
direction of the change in the velocity vector?
a) The change in velocity vector is to the left.
b) The change in velocity vector is to the right.
c) The change in velocity vector is zero because the
velocity is constant.
d) It is impossible to determine the direction of the
change in velocity vector from the given
information.
© 2014 Pearson Education, Inc.
If the velocity change arrows are all the same,
what can we conclude?
a)
b)
c)
d)
e)
The object is speeding up steadily.
The object is slowing down steadily.
The object is moving at constant speed.
The object cannot be moving.
Either A or B could be possible.
© 2014 Pearson Education, Inc.
If the velocity change arrows are all the same,
what can we conclude?
a)
b)
c)
d)
e)
The object is speeding up steadily.
The object is slowing down steadily.
The object is moving at constant speed.
The object cannot be moving.
Either A or B could be possible.
© 2014 Pearson Education, Inc.
If the velocity change arrows point in the opposite
direction as the velocity arrows, what can we
conclude?
a)
b)
c)
d)
The object is speeding up steadily.
The object is slowing down steadily.
The object is moving at constant speed.
None of the above.
© 2014 Pearson Education, Inc.
If the velocity change arrows point in the opposite
direction as the velocity arrows, what can we
conclude?
a)
b)
c)
d)
The object is speeding up steadily.
The object is slowing down steadily.
The object is moving at constant speed.
None of the above.
© 2014 Pearson Education, Inc.
Which information about a moving object can we
NOT extract from a motion diagram?
a) What the object was doing before the first dot of
the motion diagram
b) Where the object is at specific times
c) What the object's velocity is at specific times
d) How the object's velocity is changing
© 2014 Pearson Education, Inc.
Which information about a moving object can we
NOT extract from a motion diagram?
a) What the object was doing before the first dot
of the motion diagram
b) Where the object is at specific times
c) What the object's velocity is at specific times
d) How the object's velocity is changing
© 2014 Pearson Education, Inc.
Which of the following statements is true?
a)
b)
c)
d)
Displacement and distance are always the same.
Path length and distance are always the same.
Position is always the same as distance.
Distance is always the length of the displacement.
© 2014 Pearson Education, Inc.
Which of the following statements is true?
a)
b)
c)
d)
Displacement and distance are always the same.
Path length and distance are always the same.
Position is always the same as distance.
Distance is always the length of the
displacement.
© 2014 Pearson Education, Inc.
A person starts at xi = –2.0 m and ends
at xf = 3.0 m.
Given the ground as a reference frame and a
coordinate axis pointing to the right, which of the
following is NOT FALSE ?
a) The displacement vector points to the left.
b) The value of the displacement dx is –5.0 m.
c) The value of the displacement dx is +5.0 m.
d) The distance traveled is –5.0 m.
© 2014 Pearson Education, Inc.
A person starts at xi = –2.0 m and ends
at xf = 3.0 m.
Given the ground as a reference frame and a
coordinate axis pointing to the right, which of the
following is NOT FALSE ?
a) The displacement vector points to the left.
b) The value of the displacement dx is –5.0 m.
c) The value of the displacement dx is +5.0 m.
d) The distance traveled is –5.0 m.
© 2014 Pearson Education, Inc.
Sammy went hiking between two camps that were
separated by about 10 kilometers (km). He hiked
approximately 16 km to get from one camp to the
other. Which of the following is the CORRECT
translation of 10 km and 16 km into the language of
physical quantities?
a) 10 km is the displacement; 16 km is the distance.
b) 10 km is the initial position xi; 16 km is the final
position xf.
c) 16 km is the displacement; 10 km is the distance.
d) 16 km is the path length; 10 km is the distance.
© 2014 Pearson Education, Inc.
Sammy went hiking between two camps that were
separated by about 10 kilometers (km). He hiked
approximately 16 km to get from one camp to the
other. Which of the following is the CORRECT
translation of 10 km and 16 km into the language of
physical quantities?
a) 10 km is the displacement; 16 km is the distance.
b) 10 km is the initial position xi; 16 km is the final
position xf.
c) 16 km is the displacement; 10 km is the distance.
d) 16 km is the path length; 10 km is the distance.
© 2014 Pearson Education, Inc.
By drawing the graph from the motion diagram,
what are we NOT able to do?
a) Infer the position of the
object for times between
the ones where
measurements were taken
b) Infer the position of the
object before the initial point
in the motion diagram
c) Infer a trend in the observed
motion data
© 2014 Pearson Education, Inc.
By drawing the graph from the motion diagram,
what are we NOT able to do?
a) Infer the position of the
object for times between
the ones where
measurements were taken
b) Infer the position of the
object before the initial
point in the motion diagram
c) Infer a trend in the observed
motion data
© 2014 Pearson Education, Inc.
What can we infer from the following graph?
a) The object's motion ends
when it reaches 10 m
from the origin.
b) The object gets farther
from the origin with time.
c) The object started to the
left of the origin.
d) The object's final position
is above its initial position.
© 2014 Pearson Education, Inc.
What can we infer from the following graph?
a) The object's motion ends
when it reaches 10 m
from the origin.
b) The object gets farther
from the origin with time.
c) The object started to the
left of the origin.
d) The object's final position
is above its initial position.
© 2014 Pearson Education, Inc.
Which of the following statements is always true
about the description of motion of an object
by two observers?
(Be prepared to give a counter-example for each
situation you think is incorrect.)
a) Two observers using the same reference frame will
always have the same description of motion.
b) Two observers using the same coordinate axis
(including the origin) will always have the same
description of motion.
c) Two observers using the same coordinate axis
(including the origin) and reference frame will
always have the same description of motion.
© 2014 Pearson Education, Inc.
Which of the following statements is always true
about the description of motion of an object
by two observers?
(Be prepared to give a counter-example for each
situation you think is incorrect.)
a) Two observers using the same reference frame will
always have the same description of motion.
b) Two observers using the same coordinate axis
(including the origin) will always have the same
description of motion.
c) Two observers using the same coordinate axis
(including the origin) and reference frame will
always have the same description of motion.
© 2014 Pearson Education, Inc.
Which of the following statements is consistent with
what the variables indicate for the general linear
function y(x) = kx + b?
a)
b)
c)
d)
e)
The variable x depends on y.
b is the slope of the line.
y is the slope of the line.
b is the y-intercept.
k is the y-intercept.
© 2014 Pearson Education, Inc.
Which of the following statements is consistent with
what the variables indicate for the general linear
function y(x) = kx + b?
a)
b)
c)
d)
e)
The variable x depends on y.
b is the slope of the line.
y is the slope of the line.
b is the y-intercept.
k is the y-intercept.
© 2014 Pearson Education, Inc.
Which parameter can we NOT determine from
the following graph?
a)
b)
c)
d)
Initial position x0
Speed of the object
Velocity of the object
Position of the object
at time t = 3 s
e) Position of the object at t = 8 s
© 2014 Pearson Education, Inc.
Which parameter can we NOT determine from
the following graph?
a)
b)
c)
d)
Initial position x0
Speed of the object
Velocity of the object
Position of the object
at time t = 3 s
e) Position of the object at t = 8 s
© 2014 Pearson Education, Inc.
What can we conclude about the motion of car A
compared to car B?
a) Car A and car B are not at
the same location at t = 0.
b) Car B is 1 m ahead of car A
at t = 4 s.
c) Car B is moving faster than
car A.
d) Both cars are moving in
the –x direction.
e) Car A is moving faster than car B.
© 2014 Pearson Education, Inc.
What can we conclude about the motion of car A
compared to car B?
a) Car A and car B are not at
the same location at t = 0.
b) Car B is 1 m ahead of car A
at t = 4 s.
c) Car B is moving faster than
car A.
d) Both cars are moving in
the –x direction.
e) Car A is moving faster than car B.
© 2014 Pearson Education, Inc.
A cyclist moves at a constant velocity of –8 m/s and
starts at x0 = 0 m. Which of the following
statements is incorrect?
a) The cyclist has a speed of 8 m/s.
b) The cyclist has moved 8 meters after 1 second has
passed.
c) The cyclist is at x = +8 m at t = 1 s.
d) The cyclist is at x = –8 m at t = 1 s.
© 2014 Pearson Education, Inc.
A cyclist moves at a constant velocity of –8 m/s and
starts at x0 = 0 m. Which of the following
statements is incorrect?
a) The cyclist has a speed of 8 m/s.
b) The cyclist has moved 8 meters after 1 second has
passed.
c) The cyclist is at x = +8 m at t = 1 s.
d) The cyclist is at x = –8 m at t = 1 s.
© 2014 Pearson Education, Inc.
Compare two objects (positions are in meters,
time is in seconds):
x1 = 5t + 3
x2 = –4t + 0
Which of the following is incorrect?
a) Object 2 starts at the origin.
b) Object 1 and object 2 are moving in opposite
directions.
c) Object 1 has a speed of 5 m/s.
d) Object 2 has a velocity of 4 m/s.
© 2014 Pearson Education, Inc.
Compare two objects (positions are in meters,
time is in seconds):
x1 = 5t + 3
x2 = –4t + 0
Which of the following is incorrect?
a) Object 2 starts at the origin.
b) Object 1 and object 2 are moving in opposite
directions.
c) Object 1 has a speed of 5 m/s.
d) Object 2 has a velocity of 4 m/s.
© 2014 Pearson Education, Inc.
What is the displacement of "you" between
t = 0 and t = 2 s?
a)
b)
c)
d)
0m
+3 m
+6 m
+9 m
© 2014 Pearson Education, Inc.
What is the displacement of "you" between
t = 0 and t = 2 s?
a)
b)
c)
d)
0m
+3 m
+6 m
+9 m
© 2014 Pearson Education, Inc.
What is the displacement (x – x0) between t = 0 s
and t = 2 s given that the equation for position
as a function of time is x = 3t + 0
(x in meters, t in seconds)?
a)
b)
c)
d)
0m
+3 m
+6 m
+9 m
© 2014 Pearson Education, Inc.
What is the displacement (x – x0) between t = 0 s
and t = 2 s given that the equation for position
as a function of time is x = 3t + 0
(x in meters, t in seconds)?
a)
b)
c)
d)
0m
+3 m
+6 m
+9 m
© 2014 Pearson Education, Inc.
The equation for your position as a function of
time is x = 3t + 0 (x in meters, t in seconds).
Compare that to the graph of your velocity.
Which statement is incorrect?
a) We can find the displacement
between t = 0 and t = 2 s
from the equation or the graph.
b) We can find your velocity from
either the equation or the graph.
c) We can find your initial position
from either the equation or the graph.
d) We can find your acceleration
from either the equation
or the graph.
© 2014 Pearson Education, Inc.
The equation for your position as a function of
time is x = 3t + 0 (x in meters, t in seconds).
Compare that to the graph of your velocity.
Which statement is incorrect?
a) We can find the displacement
between t = 0 and t = 2 s
from the equation or the graph.
b) We can find your velocity from
either the equation or the graph.
c) We can find your initial position
from either the equation or the graph.
d) We can find your acceleration
from either the equation
or the graph.
© 2014 Pearson Education, Inc.
Why is the following statement true? "Displacement
is equal to the area between a velocity-versus-time
graph line and the time axis with a positive or
negative sign."
a) This is consistent with the definition of the slope of
the position versus time graph.
b) This is consistent with finding the height times the
width of the velocity graph.
c) This yields a result consistent with applying the
equation for linear motion.
d) All of the above are true.
© 2014 Pearson Education, Inc.
Why is the following statement true? "Displacement
is equal to the area between a velocity-versus-time
graph line and the time axis with a positive or
negative sign."
a) This is consistent with the definition of the slope of
the position versus time graph.
b) This is consistent with finding the height times the
width of the velocity graph.
c) This yields a result consistent with applying the
equation for linear motion.
d) All of the above are true.
© 2014 Pearson Education, Inc.
Which of the following situations corresponds to a
positive acceleration?
a) An object moving in the –x direction and slowing
down
b) An object moving in the –x direction and speeding
up
c) An object moving in the +x direction and slowing
down
d) None of the above
© 2014 Pearson Education, Inc.
Which of the following situations corresponds to a
positive acceleration?
a) An object moving in the –x direction and
slowing down
b) An object moving in the –x direction and speeding
up
c) An object moving in the +x direction and slowing
down
d) None of the above
© 2014 Pearson Education, Inc.
An object has an initial velocity of –4 m/s
and a constant acceleration of 3 m/s2.
What is its velocity at t = 2 s?
a)
b)
c)
d)
–10 m/s
–2 m/s
+2 m/s
+10 m/s
© 2014 Pearson Education, Inc.
An object has an initial velocity of –4 m/s
and a constant acceleration of 3 m/s2.
What is its velocity at t = 2 s?
a)
b)
c)
d)
–10 m/s
–2 m/s
+2 m/s
+10 m/s
© 2014 Pearson Education, Inc.
What are the SI units of (1/2)axt2?
a)
b)
c)
d)
e)
s
s2
m
m/s
m/s2
© 2014 Pearson Education, Inc.
What are the SI units of (1/2)axt2?
a)
b)
c)
d)
e)
s
s2
m
m/s
m/s2
© 2014 Pearson Education, Inc.
An object starts at rest 3 m from the origin and has
an acceleration of –1 m/s2. What is its
position at t = 2 s?
a)
b)
c)
d)
–5 m
–2 m
1m
3m
© 2014 Pearson Education, Inc.
An object starts at rest 3 m from the origin and has
an acceleration of –1 m/s2. What is its
position at t = 2 s?
a)
b)
c)
d)
–5 m
–2 m
1m
3m
© 2014 Pearson Education, Inc.
The following equation describes an object's motion:
x = (2 m) + (0)t + (1/2)(–1 m/s2)t2
Which of the following statements is correct?
a)
b)
c)
d)
The object starts to the left of the origin.
The object starts with an initial velocity.
The object has constant velocity.
The object is speeding up.
© 2014 Pearson Education, Inc.
The following equation describes an object's motion:
x = (2 m) + (0)t + (1/2)(–1 m/s2)t2
Which of the following statements is correct?
a)
b)
c)
d)
The object starts to the left of the origin.
The object starts with an initial velocity.
The object has constant velocity.
The object is speeding up.
© 2014 Pearson Education, Inc.
A car's motion with respect to the ground is
described by the following function:
x = (–48 m) + (+12 m/s)t + (–0.5 m/s2)t2
Which statement is INCORRECT?
a)
b)
c)
d)
The position of the car at t = 0 is –48 m.
The initial velocity of the car is +12 m/s.
The acceleration of the car is –0.5 m/s2.
The acceleration of the car is –1.0 m/s2.
© 2014 Pearson Education, Inc.
A car's motion with respect to the ground is
described by the following function:
x = (–48 m) + (+12 m/s)t + (–0.5 m/s2)t2
Which statement is INCORRECT?
a)
b)
c)
d)
The position of the car at t = 0 is –48 m.
The initial velocity of the car is +12 m/s.
The acceleration of the car is –0.5 m/s2.
The acceleration of the car is –1.0 m/s2.
© 2014 Pearson Education, Inc.
When an object is thrown upward, what is its
acceleration (given a coordinate axis choice
where +y is downward)?
a) –9.8 m/s2
b) 0 m/22
c) 9.8 m/s2
© 2014 Pearson Education, Inc.
When an object is thrown upward, what is its
acceleration (given a coordinate axis choice
where +y is downward)?
a) –9.8 m/s2
b) 0 m/22
c) 9.8 m/s2
© 2014 Pearson Education, Inc.
At t = 0, an object is 10 m above the ground, moving
upward with a velocity of 1 m/s. Which of the
following equations correctly describes the object's
position as a function of time given a coordinate axis
where y = 0 at the ground and +y is downward?
a)
b)
c)
d)
y = (–10 m) + (–1 m/s)t + (1/2)(9.8 m/s2)t2
y = (10 m) + (–1 m/s)t + (1/2)(–9.8 m/s2)t2
y = (10 m) + (1 m/s)t + (1/2)(–9.8 m/s2)t2
y = (–10 m) + (1 m/s)t + (1/2)(9.8 m/s2)t2
© 2014 Pearson Education, Inc.
At t = 0, an object is 10 m above the ground, moving
upward with a velocity of 1 m/s. Which of the
following equations correctly describes the object's
position as a function of time given a coordinate axis
where y = 0 at the ground and +y is downward?
a)
b)
c)
d)
y = (–10 m) + (–1 m/s)t + (1/2)(9.8 m/s2)t2
y = (10 m) + (–1 m/s)t + (1/2)(–9.8 m/s2)t2
y = (10 m) + (1 m/s)t + (1/2)(–9.8 m/s2)t2
y = (–10 m) + (1 m/s)t + (1/2)(9.8 m/s2)t2
© 2014 Pearson Education, Inc.
At t = 0, an object is 30 m above the ground,
moving upward with a velocity of 1 m/s.
Where is the object at t = 2 s
(approximate g of 10 m/s2)?
a)
b)
c)
d)
10 m
12 m
48 m
50 m
© 2014 Pearson Education, Inc.
At t = 0, an object is 30 m above the ground,
moving upward with a velocity of 1 m/s.
Where is the object at t = 2 s
(approximate g of 10 m/s2)?
a)
b)
c)
d)
10 m
12 m
48 m
50 m
© 2014 Pearson Education, Inc.