UW Physics 114 Mastering Questions Exam
And Accurate Answers
Which of the following best describes how to calculate the average acceleration of any
object? - ANSWER Average acceleration is always equal to the change in velocity of an object
divided by the time interval.
The figure shows the velocity versus time graph for a car driving on a straight road. Which of
the following best describes the acceleration of the car? - ANSWER The acceleration of the car
is positive and decreasing.
On a straight road, a car speeds up at a constant rate from rest to 20 m/s over a 5 second
interval and a truck slows at a constant rate from 20 m/s to a complete stop over a 10 second
interval. How does the distance traveled by the truck compare to that of the car? - ANSWER
The truck travels twice as far as the car.
Suppose you are hiking along a trail. Make a comparison between the magnitude of your
displacement and your distance traveled. - ANSWER The magnitude of your displacement can
be equal to your distance traveled.
The magnitude of your displacement can be less than your distance traveled
Suppose a runner completes one lap around a 400-m track in a time of 50 s. Calculate the
magnitude of the average velocity of the runner. - ANSWER 0 m/s (his displacement is zero if
his starting point = his ending point)
,Suppose a runner completes one lap around a 400-m track in a time of 50 s. Calculate the
average speed of the runner. - ANSWER 8 m/s
Consulting the graph shown in (Figure 1) , determine the object's average velocity over the
time interval from 2 to 4 seconds. - ANSWER 5 m/s
Which of the motion diagrams in the figure below best matches the motion of the bungee
jumper shown in the video? - ANSWER C (Because the video only follows the free fall portion
of the jump, the correct motion diagram shows constant downward acceleration.)
Which of the following best describes the acceleration of a bungee jumper during free fall? -
ANSWER constant (Free fall acceleration is constant and has a value of 9.8 m/s^2)
Three cars drive around a perfectly circular track. The speedometers in the figure below show
the speed of each car over the same 10-s time interval. Which of the cars are accelerating? -
ANSWER Cars A, B, and C (All three cars are accelerating because the directions of their
velocity vectors change constantly as they drive in a circle. In addition, the speeds of cars A
and B are changing, which also indicates acceleration.)
Four cars undergo acceleration as described by the data in the following table. - ANSWER Car
B, Car A, Car D, Car C (Correct
The average accelerations, from most positive to most negative, are as follows: (B) 4 m/s2, (A)
3 m/s2, (D) 2.5 m/s2, and (C) −3 m/s2.)
,Suppose that you toss a rock upward so that it rises and then falls back to the earth. If the
acceleration due to gravity is 9.8 m/sec2, what is the rock's acceleration at the instant that it
reaches the top of its trajectory (where its velocity is momentarily zero)? Assume that air
resistance is negligible. - ANSWER The rock has a downward acceleration of 9.8m/s^2
On Mars, where air resistance is negligible, an astronaut drops a rock from a cliff and notes
that the rock falls about d meters during the first t seconds of its fall. Assuming the rock does
not hit the ground first, how far will it fall during the first 4t seconds of its fall? - ANSWER 16d
On the Moon, where air resistance is negligible, an astronaut drops a rock from a cliff and
notes that the rock has a speed v after falling from its point of release for a time t. Assuming
that the rock does not hit the ground first, how fast will it be moving after it has fallen for a
time 4t from its point of release? - ANSWER 4v
Which of the following equations correctly expresses the relation between vectors A⃗ , B⃗ ,
and C⃗ shown in the figure? (problem 1) - ANSWER B⃗ =A⃗ +C⃗
Vector A⃗ has a magnitude of 2.00 m and vector B⃗ has a magnitude of 5.00 m. If the direction
of each vector is unknown, what is the largest possible value for the magnitude of A⃗ −B⃗ ? -
ANSWER 7.00 m
Which of the following equations correctly expresses the relation between vectors A⃗ , B⃗ ,
and C⃗ shown in the figure? (problem 2) - ANSWER A⃗ +B⃗ +C⃗ =0
, Vector A⃗ has a magnitude of 3.00 and is directed parallel to the negative y-axis and vector B⃗
has a magnitude of 3.00 and is directed parallel to the positive y-axis. Determine the
magnitude and direction angle (as measured counterclockwise from the positive x-axis) of
vector C⃗ , if C⃗ =A⃗ −B⃗ . - ANSWER C = 6.00; θ = 270˚
Suppose that C⃗ =A⃗ −B⃗ . Under what circumstances is the length of C⃗ has to equal to the
sum of the lengths of A⃗ has and B⃗ has? - ANSWER When A⃗ and B⃗ point in opposite
directions
Starting from your campsite you walk 3.0 km east, 6.0 km north, 1.0 km east, and then 4.0 km
west. How far are you from your campsite? - ANSWER 6.0 km
Which of the following is a vector quantity? - ANSWER acceleration
velocity
momentum
force
displacement
The sum of two vectors is the largest when the two vectors are _____. - ANSWER pointing in
the same direction
The sum of the x components of vectors A and B in (Figure 1) is ___. - ANSWER 4
And Accurate Answers
Which of the following best describes how to calculate the average acceleration of any
object? - ANSWER Average acceleration is always equal to the change in velocity of an object
divided by the time interval.
The figure shows the velocity versus time graph for a car driving on a straight road. Which of
the following best describes the acceleration of the car? - ANSWER The acceleration of the car
is positive and decreasing.
On a straight road, a car speeds up at a constant rate from rest to 20 m/s over a 5 second
interval and a truck slows at a constant rate from 20 m/s to a complete stop over a 10 second
interval. How does the distance traveled by the truck compare to that of the car? - ANSWER
The truck travels twice as far as the car.
Suppose you are hiking along a trail. Make a comparison between the magnitude of your
displacement and your distance traveled. - ANSWER The magnitude of your displacement can
be equal to your distance traveled.
The magnitude of your displacement can be less than your distance traveled
Suppose a runner completes one lap around a 400-m track in a time of 50 s. Calculate the
magnitude of the average velocity of the runner. - ANSWER 0 m/s (his displacement is zero if
his starting point = his ending point)
,Suppose a runner completes one lap around a 400-m track in a time of 50 s. Calculate the
average speed of the runner. - ANSWER 8 m/s
Consulting the graph shown in (Figure 1) , determine the object's average velocity over the
time interval from 2 to 4 seconds. - ANSWER 5 m/s
Which of the motion diagrams in the figure below best matches the motion of the bungee
jumper shown in the video? - ANSWER C (Because the video only follows the free fall portion
of the jump, the correct motion diagram shows constant downward acceleration.)
Which of the following best describes the acceleration of a bungee jumper during free fall? -
ANSWER constant (Free fall acceleration is constant and has a value of 9.8 m/s^2)
Three cars drive around a perfectly circular track. The speedometers in the figure below show
the speed of each car over the same 10-s time interval. Which of the cars are accelerating? -
ANSWER Cars A, B, and C (All three cars are accelerating because the directions of their
velocity vectors change constantly as they drive in a circle. In addition, the speeds of cars A
and B are changing, which also indicates acceleration.)
Four cars undergo acceleration as described by the data in the following table. - ANSWER Car
B, Car A, Car D, Car C (Correct
The average accelerations, from most positive to most negative, are as follows: (B) 4 m/s2, (A)
3 m/s2, (D) 2.5 m/s2, and (C) −3 m/s2.)
,Suppose that you toss a rock upward so that it rises and then falls back to the earth. If the
acceleration due to gravity is 9.8 m/sec2, what is the rock's acceleration at the instant that it
reaches the top of its trajectory (where its velocity is momentarily zero)? Assume that air
resistance is negligible. - ANSWER The rock has a downward acceleration of 9.8m/s^2
On Mars, where air resistance is negligible, an astronaut drops a rock from a cliff and notes
that the rock falls about d meters during the first t seconds of its fall. Assuming the rock does
not hit the ground first, how far will it fall during the first 4t seconds of its fall? - ANSWER 16d
On the Moon, where air resistance is negligible, an astronaut drops a rock from a cliff and
notes that the rock has a speed v after falling from its point of release for a time t. Assuming
that the rock does not hit the ground first, how fast will it be moving after it has fallen for a
time 4t from its point of release? - ANSWER 4v
Which of the following equations correctly expresses the relation between vectors A⃗ , B⃗ ,
and C⃗ shown in the figure? (problem 1) - ANSWER B⃗ =A⃗ +C⃗
Vector A⃗ has a magnitude of 2.00 m and vector B⃗ has a magnitude of 5.00 m. If the direction
of each vector is unknown, what is the largest possible value for the magnitude of A⃗ −B⃗ ? -
ANSWER 7.00 m
Which of the following equations correctly expresses the relation between vectors A⃗ , B⃗ ,
and C⃗ shown in the figure? (problem 2) - ANSWER A⃗ +B⃗ +C⃗ =0
, Vector A⃗ has a magnitude of 3.00 and is directed parallel to the negative y-axis and vector B⃗
has a magnitude of 3.00 and is directed parallel to the positive y-axis. Determine the
magnitude and direction angle (as measured counterclockwise from the positive x-axis) of
vector C⃗ , if C⃗ =A⃗ −B⃗ . - ANSWER C = 6.00; θ = 270˚
Suppose that C⃗ =A⃗ −B⃗ . Under what circumstances is the length of C⃗ has to equal to the
sum of the lengths of A⃗ has and B⃗ has? - ANSWER When A⃗ and B⃗ point in opposite
directions
Starting from your campsite you walk 3.0 km east, 6.0 km north, 1.0 km east, and then 4.0 km
west. How far are you from your campsite? - ANSWER 6.0 km
Which of the following is a vector quantity? - ANSWER acceleration
velocity
momentum
force
displacement
The sum of two vectors is the largest when the two vectors are _____. - ANSWER pointing in
the same direction
The sum of the x components of vectors A and B in (Figure 1) is ___. - ANSWER 4
