physics final
the graph below shows the motion of four objects. Which of the following lines represent an abject in free fall? assume positive velocity is upward.
I and III
rank in decreasing order the displacements of objects having the following pairs of average velocity and time of motion. I. vag=+2.0m/s, "triangle"t=2.0s II. vag=+3.0m/s, "triangle"t=2.0s III. vag=-3.0m/s, "triangle"t=3.0s
II, I, III
rank in decreasing order the distances traveled by objects having the following pairs of average velocity and time of motion. I. vag=+2.0m/s, "triangle"t=2.0s II. vag=+3.0m/s, "triangle"t=2.0s III. vag=-3.0m/s, "triangle"t=3.0s
III, II, I
all of the following are unit abbreviations except which one?
"triangle" y
which of the following equations est shows the average relationship between temperature and time for substance B as given in Table 1 and Graph 1?
"triangle"T= 0.07("triangle"t)
a red ball is dropped from rest and undergoes free fall. one second later a blue ball is dropped from rest and undergoes free fall. - the red ball's change of velocity during the thirst second of the demonstration is "triangle"v2-3. what is the change of velocity of the blue ball during this time interval?
"triangle"v2-3
the displacement of an object undergoing free fall from rest is proportional to. . .
("triangle"t)^2
a red ball is dropped from rest and undergoes free fall. one second later a blue ball is dropped from rest and undergoes free fall. - the displacement of the blue ball during the time intervak 3.0-4.0s is equal to the displacement of the red ball in which of the following intervals of the demonstration?
2.0-3.0s
a red ball is dropped from rest and undergoes free fall. one second later a blue ball is dropped from rest and undergoes free fall. - the red ball's velocity at the end of 3.0 seconds is v3. what is the blue ball's velocity at this moment of the demonstration?
2/3v3
what does the symbol "triangle"m represent?
a change in mass
the projection of a vector along the axes of a coordinate system is called . . .
a component of the vector
what does graph 1 show about the heating rate of substance A versus substance B?
compared to substance B, substance A has a faster heating rate; compared to substance A, substance B has a slower heating rate; substances A and B heat at different rates (all of the above)
a bicycle courier accepts a package and bikes 3 blocks east to the intersection of the street shown on the address label. encountering road construction, the biker detours by continuing one block east, one block north, and one block west. the biker then bikes 2 blocks north to the address. what's the resultant displacement of the biker? use the graphical method.
d = 4.2 blocks 45 degrees n of e
which of the displacements, when added in the order given, will yield a displacement equal to d1+d2+d3?
d2+d1+d3
describe the dog's motion when it is at 1.0m.
dog's acceleration is equal to zero for 2 seconds
an object in free fall. . .
experiences no air resistance, undergoes a downward acceleration, and has an acceleration with a magnitude of 9.81m/s^2 near Earth's surface (all of the above)
Models can do all of the following EXCEPT ____.
explain every aspect of natural phenomena
what is the first step toward simplifying a complicated situation, and what are three ways to summarize a complicated situation?
first step is to define the system 1. build computer simulation/small scale replica of the situation 2. only focus on one part at a time 3. conduct a controlled experiment
which of the following represents a system?
flag blowing in the wind, ball rolling on the ground, and a picture hanging on the wall (all of the above)
After making observations and collecting data that leads to a question, a physicist will then
formulate and test hypotheses by experimentation
if vectors are moved according to the rules of the triangle method of vector addition, then the resultant vector is drawn. . .
from the tail of the first vector to the tip of the last vector
a climber throws a rope with a velocity of 3.0m/s downward to another climber 4.0 m directly below. what is the rope's velocity when it reached the lower climber? assume no air resistance & that a=-g=-9.81 m/s^2
given: vi=-3.0m/s^2 a=-9.81m/s^2 "triangle"=-4.0m vf^2=vi^2 + 2a"triangle"x vf^2= +/- square root of vi^2 + 2a"triangle"x vf^2=+/- square root of (-3.0m/s^2)^2+2(-9.81m/s^2)(-4.0m)
a cat walking at 0.25 m/s sees a mouse and accelerates uniformly at 0.40 m/c^2 for 3.0s. What is the cat's displacement during this time?
given: vi=0.25m/s a=0.40m/s "triangle"t=3.0s "triangle"x=vi"triangle"t+a("triangle"t)^2/2 "triangle"x=0.25m/s x 3.0s + 0.40m/s^2 x 3.0s^2/2 "triangle"x = 1.35m
what is the dog's average velocity for the total displacement?
given: vi=3.0 vf=4.0 ti=0s tf=10.0s vag=vf-vi/tf-ti vag=4.0m-3.0m/10.0s-0s vag=1.0m/10.0s vag=.1m/s
the speed of a car will increase if the car's . . .
initial velocity is positive and its acceleration is positive
(d = m/v) a block of wood with a density of 0.80 g/cm^3 has a volume of 6.1cm^3. Find its mass in kilograms.
m=dv=0.80g/cm^3 x 6.1 cm^3 m= 4.88g or 4.9g 4.9g x 1kg / 1 x 10^3g = 0.0049kg
in a diagram, the length of a vector arrow represents the . . .
magnitude of the vector
what quantity does the kilogram measure?
mass
What is the SI base unit for length?
meter
how many variables may be tested legitimately in any one experiment?
one
a vector remains unchanged. . .
only if it is moved parallel to its original direction
the components of a vector are. . .
perpendicular
what is the correct description of any change of position farther to the right of zero?
positive displacement
a physicist who studies the behavior of submicroscopic particles is working in which area within physics?
quantum mechanics
what is the standard abbreviation for seconds?
s
describe a situation that uses the processes of the scientific method. Explain how the scientific processes are used in that situation.
school science fair project (make observations and research, form hypothesis w/experiments, form conclusion based on results.
how many significant figures does 50.003 00 have?
seven
in a school playground, a child runs 5m in the x-direction and then 2.0 m in the -y-direction. which of the following expressions represented the magnitude of the child's resultant displacement?
square root of (5m)^2 + (-2m)^2
How do significant figures indicate a measurement's precision?
the greater the precision of the instrument, the greater number of significant figures
for a scooter with a negative acceleration, which of the following statements is always true?
the initial velocity of he scooter will be greater than its final velocity
precision describes. . .
the limitations of the measuring instrument
the final velocity of an object undergoing free fall from rest is proportional to. . .
the square root of ("triangle"x)
measuring temperature would most likely involve which major area in physics?
thermodynamics
Why do physicists use models?
they are helpful when explaining fundamental features
name at least 2 advantages for using equations.
they describe the relationship between variables and they are used to produce graphs and to make predictions
if the final answer's dimension is to be in length, which of the following operations is correct?
time x (length/time) time x length/time = length
an object in free fall. . .
undergoes a velocity decrease of 9.81m/s during each second
the average acceleration is the ratio of which of the following quantities?
v:"triangle"t
what is the major difference between a vector quantity and a scalar quantity?
vector quantity is described by direction and magnitude, but scalar quantity is only described by magnitude
which of the following situations represents a positive displacement of a carton? assume positive position is measured vertically upward along a y-axis.
when the elevator doors open, the delivery person lifts the dolly over the threshold of the elevator
a dog walks from +4m to +2m. Which of the following statements is true about the dog's motion?
xf = +2m
what is the maximum negative displacement a dog could have if it started its motion at +3m?
-3m
the average mass of a proton is 1.673 x 10^-27 kg. What is this mass in grams?
1.673 x 10^-24 g (1.673 x 10^-27 kg x 1 x 10^3 g / 1 kg = 1.673 x 10^-24 g)
calculate the area of a room whose length is 15.23 m and width is 8.7 m. Express your answer in scientific notation and with the correct number of significant digits.
15.23 m x 8.7 m = 132.501 m^2 1.3 x 10^2 m^2 (only 2 significant digits)
use the factor-label method to convert 470km into mm. Report in scientific notation correctly rounded.
1km = 1 x 10^6 mm 470km x 1 x 10^6 mm/1km = 4.7 x 10^8 mm
find the 5 time intervals shown, during how many intervals does the dog have the same average velocity?
2
for the 5 time intervals shown, during how many intervals does the dog pace at the same average velocity?
3
in scientific notation, 0.000 005 823 ug equals. . .
5.823 x 10^-6 ug
in a diagram, a student draws a vector representing the velocity of a plane traveling at 525km/h 18.0 degree east of north as a vector lying along the +x-axis. to represent the velocity of another plane traveling at 478km/h 75.0degrees e of n on the diagram, @ what orientation w/respect to the +x-axis should the student draw this vector?
57.0degrees clockwise from the +x-axis
solve and round correctly: 4.817 x 10^3m/8.12 x 10^2s
59322.6601m/s 59300 m/s
in scientific notation, 674.3mm equals. . .
6.743 x 10^2mm
the accepted value for d=free-fall acceleration is 9.806 65 m/s^2. which of the following measurements is the most accurate?
9.808 60 m/s^2
a vector that has components the lie along the -x-axis & the +y-axis is oriented at angle A measured counterclockwise from the from +x-axis. which of the following ranges give the values of angle A?
90 degrees < A < 180 degrees
during which of the following intervals is the speed of the jogger decreasing?
AB and CD
during which of the following intervals does the jogger have a constant positive velocity?
BC
if the x-component of B equals the magnitude of b, then. . .
By equals zero
the jogger is at rest during which interval?
DE
during which interval is the magnitude of the jogger's acceleration the greatest?
EF
during which of the following intervals is the jogger's motion toward home?
EF and FG
Physics is concerned with which of the following matters?
applying physics principles, describing the physical world, and making predictions about a broad range of phenomena (all of the above)
based on the data from table 1, which of the following statements is correct?
as time increased, the temperature increased for both substances
which of the following quantities used to describe motion is an example of a vector quantity?
average velocity
