Deck 2: Describing Motion: Kinematics in One Dimension

Question 1

Choose the one alternative that best completes the statement or answers the question.
What must be your average speed in order to travel 350 km in 5.15 h?

A) 66.0 km/h
B) 69.0 km/h
C) 68.0 km/h
D) 67.0 km/h

Answer 1

68.0 km/h

Question 2

Choose the one alternative that best completes the statement or answers the question.
A light-year is the distance that light travels in one year. The speed of light is 3.00 × 108 m/s. How many miles are there in one light-year? (1 mi = 1609 m, 1 y = 365 d)

A) 5.88 × 1015 mi
B) 9.46 × 1012 mi
C) 5.88 × 1012 mi
D) 9.46 × 1015 mi

Answer 2

5.88 × 1012 mi

Question 3

Write the word or phrase that best completes each statement or answers the question.
If you run a complete loop around an outdoor track of length 400 m in 100 s, find your
(a) average velocity and (b) average speed.

Answer 3

(a) 0 m/s (b) 4 m/s

Question 4

Choose the one alternative that best completes the statement or answers the question.
A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m. She completes one lap in 100 seconds. What is her average
Velocity?

A) 1.3 m/s
B) 2.5 m/s
C) 0 m/s
D) 5.0 m/s
E) 10 m/s

Question 5

Choose the one alternative that best completes the statement or answers the question.
You leave on a 549-mi trip in order to attend a meeting that will start 10.8 h after you begin your trip. Along the way you plan to stop for dinner. If the fastest you can safely drive is 65 mi/h, what
Is the longest time you can spend over dinner and still arrive just in time for the meeting?

A) 2.6 h
B) 1.9 h
C) 2.4 h
D) You can't stop at all.

Question 6

Write the word or phrase that best completes each statement or answers the question.
A bat, flying toward the east at 2.0 m/s, emits a shriek that is reflected back to it from a
wall that is 20.0 m in front of the bat at the instant the shriek is emitted. Sound travels at
340 m/s in the air. How many milliseconds after emitting the shriek does the bat hear the
reflected echo from the wall?

Question 7

Choose the one alternative that best completes the statement or answers the question.
An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the trip?

A) 280 mi/h
B) 270 mi/h
C) 275 mi/h
D) 260 mi/h

Question 8

Choose the one alternative that best completes the statement or answers the question.
A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. What was the average speed of the runner in m/s?

A) 14,200 m/s
B) 124 m/s
C) 14.2 m/s
D) 3.95 m/s

Question 9

Choose the one alternative that best completes the statement or answers the question.
A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip?

A) 88 km/h
B) 92 km/h
C) 90 km/h
D) 85 km/h

Question 10

Choose the one alternative that best completes the statement or answers the question.
A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 45 min. What was the bear's average speed?

A) 4.0 km/h
B) 0.00 km/h
C) 0.067 km/h
D) 5.3 km/h

Question 11

Choose the one alternative that best completes the statement or answers the question.
A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this trip?

A) 91 km/h
B) 90 km/h
C) 84 km/h
D) 89 km/h

Question 12

Choose the one alternative that best completes the statement or answers the question.
A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m. She completes one lap in 100 seconds. What is her average
Speed?

A) 5.0 m/s
B) 10 m/s
C) 0 m/s
D) 2.5 m/s
E) 1.3 m/s

Question 13

Choose the one alternative that best completes the statement or answers the question.
You are driving home on a weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is your
Hometown from school?

A) 200 mi
B) 180 mi
C) 210 mi
D) 190 mi

Question 14

Choose the one alternative that best completes the statement or answers the question.
A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 45 min. What was the bear's average velocity?

A) 0.00 km/h
B) 4.0 km/h
C) 0.067 km/h
D) 5.3 km/h

Question 15

Write the word or phrase that best completes each statement or answers the question.
If, in the figure, you start from the Bakery, travel to the Cafe, and then to the Art Gallery
(a) what distance you have traveled?
(b) what is your displacement?

Question 16

Write the word or phrase that best completes each statement or answers the question.
A race car circles 10 times around a circular 8.0-km track in 20 min. Using SI units
(a) what is its average speed for the ten laps?
(b) what is its average velocity for the ten laps?

Question 17

Write the word or phrase that best completes each statement or answers the question.
If, in the figure, you start from the Bakery, travel to the Cafe, and then to the Art Gallery in
2.00 hours, what is your
(a) average speed?
(b) average velocity?

Question 18

Choose the one alternative that best completes the statement or answers the question.
If you are driving 72 km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive period?

A) 18 m
B) 20 m
C) 80 m
D) 40 m

Question 19

Choose the one alternative that best completes the statement or answers the question.
A motorist makes a trip of 180 miles. For the first 90 miles she drives at a constant speed of 30 mph. At what constant speed must she drive the remaining distance if her average speed for the
Total trip is to be 40 mph?

A) 55 mph
B) 60 mph
C) 52.5 mph
D) 45 mph
E) 50 mph

Question 20

Choose the one alternative that best completes the statement or answers the question.
An object moves 15.0 m north and then 11.0 m south. Find both the distance it has traveled and the magnitude of its displacement.

A) 4.0 m, 4.0 m
B) 26.0 m, 4.0 m
C) 26.0 m, 26.0 m
D) 4.0 m, 26.0 m

Question 21

Write the word or phrase that best completes each statement or answers the question.
If a car accelerates at a uniform how long will it take to reach a speed of 80 km/hr, starting from rest?

Question 22

Write the word or phrase that best completes each statement or answers the question.
An auto accelerates forward from 7.0 m/s at a uniform It travels a distance of 1.033 km while accelerating.
(a) How fast is the auto moving just as it is traveled the 1.033 km ?
(b) How many seconds did it take to travel the 1.033 km?

Question 23

Choose the one alternative that best completes the statement or answers the question.
A car travels at 15 m/s for 10 s. It then speeds up with a constant acceleration of for 15 s. At the end of this time, what is its velocity?

A) 45 m/s
B) 15 m/s
C) 30 m/s
D) 375 m/s

Question 24

Choose the one alternative that best completes the statement or answers the question.
A car initially traveling at 60 km/h accelerates at a constant rate of
How much time is required for the car to reach a speed of 90 km/h ?

A) 4.2 s
B) 15 s
C) 45 s
D) 30 s

Question 25

Choose the one alternative that best completes the statement or answers the question.
A car starting from rest accelerates at a constant for 10 s. It then travels with constant speed it has achieved for another 10 s. Then it finally slows to a stop with constant acceleration of magnitude
How far does it travel after starting?

A) 200 m
B) 500 m
C) 400 m
D) 300 m

Question 26

Write the word or phrase that best completes each statement or answers the question.
A water rocket can reach a speed of 75 m/s in 0.050 seconds from launch. What is its
average acceleration?

Question 27

Choose the one alternative that best completes the statement or answers the question.
A cart starts from rest and accelerates uniformly at for 5.0 s. It next maintains the velocity it has reached for 10 s. Then it slows down at a steady rate of for 4.0 s. What is the final speed of the car?

A) 10 m/s
B) 16 m/s
C) 12 m/s
D) 20 m/s

Question 28

Choose the one alternative that best completes the statement or answers the question.
A certain test car can go from rest to 32.0 m/s in 3.88 s. The same car can come to a full stop from that speed in 4.14 s. What is the ratio of the magnitude of the starting acceleration to the stopping
Acceleration?

A) 1.07
B) 0.937
C) 1.14
D) 0.878

Question 29

Choose the one alternative that best completes the statement or answers the question.
The velocity of a particle as a function of time is given by What is the average acceleration of the particle between t=1.0 s and t=2.0 s?

A)
B)
C)
D)
E)

Question 30

Choose the one alternative that best completes the statement or answers the question.
A cart with an initial velocity of 5.0 m/s to the right experiences a constant acceleration of to the right. What is the cart's displacement during the first 6.0 s of this motion?

A) 10 m
B) 80 m
C) 55 m
D) 66 m

Question 31

Write the word or phrase that best completes each statement or answers the question.
Arthur and Betty start walking toward each other when they are 100 m apart. Arthur has
a speed of 3.0 m/s and Betty has a speed of 2.0 m/s. How long does it take for them to
meet?

Question 32

Write the word or phrase that best completes each statement or answers the question.
Human reaction times are worsened by alcohol. How much further (in feet) would a drunk
driver's car travel before he hits the brakes than a sober driver's car? Assume that both are
initially traveling at 50.0 mi/h and their cars have the same acceleration while slowing
down, and that the sober driver takes 0.33 s to hit the brakes in a crisis, while the drunk
driver takes 1.0 s to do so. (5280 ft = 1 mi)

Question 33

Write the word or phrase that best completes each statement or answers the question.
The captain orders his starship to accelerate from rest at a rate of How many days does it take the starship to reach 10 % the speed of light? (Light travels at

Question 34

Write the word or phrase that best completes each statement or answers the question.
The position x(t) of a particle as a function of time t is given by the equation

What is the average velocity of the particle between t=0.30 s and t=
0.40 s?

Question 35

Choose the one alternative that best completes the statement or answers the question.
A car is traveling north at 17.7 m/s. After 12 s its velocity is 14.1 m/s in the same direction. Find the magnitude and direction of the car's average acceleration.

A)
B)
C)
D)

Question 36

Choose the one alternative that best completes the statement or answers the question.
A jet plane is launched from a catapult on an aircraft carrier. In 2.0 s it reaches a speed of 42 m/s at the end of the catapult. Assuming the acceleration is constant, how far did it travel during those
2)0 s?

A) 24 m
B) 42 m
C) 16 m
D) 84 m

Question 37

Write the word or phrase that best completes each statement or answers the question.
A car that is initially moving at 7.50 m/s begins to accelerate forward uniformly at 0.550
(a) How long after beginning to accelerate does it take the car to move 3.50 km?
(b) How fast is the car moving just as it has traveled 3.50 km?

Question 38

Choose the one alternative that best completes the statement or answers the question.
An airplane increases its speed at the average rate o . How much time does it take to increase its speed from 100 m/s to 160 m/s?

A) 0.25 s
B) 4.0 s
C) 0.058 s
D) 17 s

Question 39

Choose the one alternative that best completes the statement or answers the question.
A racquetball strikes a wall with a speed of 30 m/s and rebounds in the opposite direction with a speed of 26 m/s. The collision takes 20 ms. What is the average acceleration of the ball during the collision with the wall?

A)
B)
C)
D)
E)

Question 40

Write the word or phrase that best completes each statement or answers the question.
In a ballistics test, a bullet moving horizontally with a speed of 500 m/s strikes a sandbag
and penetrates a distance of 10.0 cm.
(a) What is the magnitude of the average acceleration of the bullet in the sandbag?
(b) How many milliseconds does it take the bullet to come to rest in the sandbag?

Question 41

Choose the one alternative that best completes the statement or answers the question.
A train starts from rest and accelerates uniformly until it has traveled 5.6 km and acquired a forward velocity of 42 m/s. The train then moves at a constant velocity of 42 m/s for 420 s. The train then slows down uniformly at until it is brought to a halt. The acceleration during the first 5.6 km of travel is closest to which of the following?

A)
B)
C)
D)
E)

Question 42

Choose the one alternative that best completes the statement or answers the question.
A car increases its forward velocity uniformly from 40 m/s to 80 m/s while traveling a distance of 200 m. What is its acceleration during this time?

A)
B)
C)
D)

Question 43

Choose the one alternative that best completes the statement or answers the question.
A car is moving with a speed of 32.0 m/s. The driver sees an accident ahead and slams on the brakes, causing the car to slow down with a uniform acceleration of magnitude 3 How far
Does the car travel after the driver put on the brakes until it comes to a stop?

A) 9.14 m
B) 146 m
C) 292 m
D) 112 m
E) 4.57 m

Question 44

Choose the one alternative that best completes the statement or answers the question.
An airplane starts from rest and accelerates at a constant 10 What is its speed at the end of a 400 m-long runway?

A) 65.7 m/s
B) 186 m/s
C) 93.0 m/s
D) 37.0 m/s
E) 4320 m/s

Question 45

Choose the one alternative that best completes the statement or answers the question.
An object is moving in a straight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time?

A) 48 m
B) 57 m
C) 30 m
D) 39 m

Question 46

Choose the one alternative that best completes the statement or answers the question.
An airplane needs to reach a forward velocity of 203.0 km/h to take off. On a 2000-m runway, what is the minimum uniform acceleration necessary for the plane to take flight if it starts from rest?

A)
B)
C)
D)

Question 47

Choose the one alternative that best completes the statement or answers the question.
A train starts from rest and accelerates uniformly until it has traveled 2.1 km and acquired a forward velocity of 24 m/s. The train then moves at a constant velocity of 24 m/s for 400 s. The train then slows down uniformly at until it is brought to a halt. The distance traveled by the train while slowing down is closest to

A) 4.4 km.
B) 3.6 km.
C) 4.2 km.
D) 4.0 km.
E) 3.8 km.

Question 48

Choose the one alternative that best completes the statement or answers the question.
A car starts from rest and accelerates at a steady How far does it travel in the first 3.00

A) 9.00 m
B) 36.0 m
C) 54.0 m
D) 18.0 m
E) 27.0 m

Question 49

Choose the one alternative that best completes the statement or answers the question.
A car accelerates from 5.0 m/s to 21 m/s at a constant rate of How far does it travel while accelerating?

A) 69 m
B) 41 m
C) 117 m
D) 207 m

Question 50

Choose the one alternative that best completes the statement or answers the question.
Assuming equal rates of uniform acceleration in both cases, how much further would you travel if braking from 56 mi/h to rest than from 28 mi/h?

A) 3.2 times farther
B) 4 times farther
C) 5.2 times farther
D) 4.8 times farther

Question 51

Choose the one alternative that best completes the statement or answers the question.
A car is moving with a constant acceleration. At time t = 5.0 s its velocity is 8.0 m/s in the forward direction, and at time t = 8.0 s its velocity is 12.0 m/s forward. What is the distance traveled in that
Interval of time?

A) 10 m
B) 20 m
C) 30 m
D) 50 m
E) 40 m

Question 52

Write the word or phrase that best completes each statement or answers the question.
A car with good tires on a dry road can decelerate (slow down) at a steady rate of about when braking. If a car is initially traveling at 55 mi/h
(a) how much time does it take the car to stop?
(b) what is its stopping distance?

Question 53

Choose the one alternative that best completes the statement or answers the question.
Acceleration is sometimes expressed in multiples of where is the acceleration of an object due to the earth's gravity. In a car crash, the car's forward velocity may go from 29 m/s to 0 m/s in 0.15 s. How many g 's are experienced, on average, by the driver?

A)
B)
C)
D)

Question 54

Write the word or phrase that best completes each statement or answers the question.
A soccer ball is released from rest at the top of a grassy incline. After 6.4 seconds the ball has rolled 91 m with constant acceleration, and 1.0 s later it reaches the bottom of the incline.
(a) What was the ball's acceleration?
(b) How long was the incline?

Question 55

Choose the one alternative that best completes the statement or answers the question.
A baseball is hit with a bat and, as a result, its direction is completely reversed and its speed is doubled. If the actual contact with the bat lasts 0.45 s, what is the ratio of the magnitude of the
Average acceleration of the ball to its original speed?

A)
B)
C)
D)

Question 56

Choose the one alternative that best completes the statement or answers the question.
A car starts from rest and accelerates uniformly at toward the north. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at toward the north. How long after the second car starts does it overtake the first car?

A) 21 s
B) 24 s
C) 12 s
D) 19 s

Question 57

Write the word or phrase that best completes each statement or answers the question.
At the instant a traffic light turns green, a car that has been waiting at the intersection starts ahead with a constant acceleration of
At that moment a truck traveling with a constant velocity of 15.0 m/s overtakes and passes the car.
(a) Calculate the time necessary for the car to reach the truck.
(b) Calculate the distance beyond the traffic light that the car will pass the truck.
(c) Determine the speed of the car when it passes the truck.

Question 58

Choose the one alternative that best completes the statement or answers the question.
An object starts from rest and undergoes uniform acceleration. During the first second it travels 5.0 m. How far will it travel during the third second?

A) 15 m
B) 5.0 m
C) 45 m
D) 25 m

Question 59

Choose the one alternative that best completes the statement or answers the question.
A bicyclist starts a timed race at 6.0 mi/h. In order to win, he must average 21 mi/h. Assuming constant acceleration from the start, how fast must he be traveling at the end of the race?

A) 36 mi/h
B) 42 mi/h
C) 30 mi/h
D) 24 mi/h

Question 60

Choose the one alternative that best completes the statement or answers the question.
Starting from rest, a dragster travels a straight 1/4 mi racetrack in 6.70 s with constant acceleration. What is its velocity when it crosses the finish line?

A) 269 mi/h
B) 296 mi/h
C) 188 mi/h
D) 135 mi/h

Question 61

Choose the one alternative that best completes the statement or answers the question.
A laser is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is and there is no atmosphere. How long does it take for the laser to reach the maximum height?

A) 16 s
B) 11 s
C) 14 s
D) 8.0 s

Question 62

Choose the one alternative that best completes the statement or answers the question.
A ball is projected upward at time t = 0 s, from a point on a flat roof 90 m above the ground. The ball rises and then falls with insignificant air resistance, missing the roof, and strikes the ground.
The initial velocity of the ball is 80.5 m/s. Consider all quantities as positive in the upward
Direction. The vertical velocity of the ball when it is 89 m above the ground is closest to

A) -81 m/s.
B) -48 m/s.
C) -32 m/s.
D) -64 m/s.
E) -97 m/s.

Question 63

Choose the one alternative that best completes the statement or answers the question.
A car is traveling with a constant speed of 30.0 m/s when the driver suddenly applies the brakes, causing the car to slow down with a constant acceleration. The car comes to a stop in a distance of 120 m. What was the acceleration of the car as it slowed down?

A)
B)
C)
D)
E)

Question 64

Choose the one alternative that best completes the statement or answers the question.
A car is traveling with a constant speed when the driver suddenly applies the brakes, causing the car to slow down with a constant acceleration of magnitude 3. . If the car comes to a stop in
A distance of 30.0 m, what was the car's original speed?

A) 10.2 m/s
B) 14.5 m/s
C) 315 m/s
D) 105 m/s
E) 210 m/s

Question 65

Choose the one alternative that best completes the statement or answers the question.
A ball is thrown downward from the top of a building with an initial speed of 25 m/s. It strikes the ground after 2.0 s. How high is the building, assuming negligible air resistance?

A) 30 m
B) 70 m
C) 20 m
D) 50 m

Question 66

Write the word or phrase that best completes each statement or answers the question.
A ball is thrown straight up with a speed of 30 m/s, and air resistance is negligible.
(a) How long does it take the ball to reach the maximum height?
(b) What is the maximum height reached by the ball?
(c) What is its speed after 4.2 s?

Question 67

Choose the one alternative that best completes the statement or answers the question.
A test rocket at ground level is fired straight up from rest with a net upward acceleration of 20 m/s². After 4.0 s, the motor turns off but the rocket continues to coast upward with insignificant air
Resistance. What maximum elevation does the rocket reach?

A) 330 m
B) 320 m
C) 490 m
D) 410 m
E) 160 m

Question 68

Choose the one alternative that best completes the statement or answers the question.
A ball is thrown straight up with a speed of 36 m/s. How long does it take to return to its starting point, assuming negligible air resistance?

A) 7.3 s
B) 3.7 s
C) 15 s
D) 11 s

Question 69

Choose the one alternative that best completes the statement or answers the question.
A laser is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is and there is no atmosphere. What is the maximum height reached by the laser?

A) 8.0 m
B) 144 m
C) 48 m
D) 18 m

Question 70

Choose the one alternative that best completes the statement or answers the question.
An instrument is thrown upward with a speed of 15 m/s on the surface of planet X where the acceleration due to gravity is and there is no atmosphere. How long does it take for the instrument to return to where it was thrown?

A) 12 s
B) 6.0 s
C) 10 s
D) 8.0 s

Question 71

Choose the one alternative that best completes the statement or answers the question.
Human reaction time is usually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it,
Assuming negligible air resistance?

A) At least 6.8 cm
B) At least 9.8 cm
C) At least 3.0 cm
D) At least 4.9 cm

Question 72

Choose the one alternative that best completes the statement or answers the question.
A stone is thrown with an initial upward velocity of 7.0 m/s and experiences negligible air resistance. If we take upward as the positive direction, what is the velocity of the stone after 0.50 s?

A) 0.00 m/s
B) 2.1 m/s
C) -4.9 m/s
D) 4.9 m/s
E) -2.1 m/s

Question 73

Choose the one alternative that best completes the statement or answers the question.
A hammer is thrown upward with a speed of 14 m/s on the surface of planet X where the acceleration due to gravity is and there is no atmosphere. What is the speed of the hammer after 8.0 s?

A) 64 m/s
B) 14 m/s
C) 21 m/s
D) 7.0 m/s

Question 74

Choose the one alternative that best completes the statement or answers the question.
A bullet shot straight up returns to its starting point in 10 s. What is the initial speed of the bullet, assuming negligible air resistance?

A) 25 m/s
B) 49 m/s
C) 9.8 m/s
D) 98 m/s

Question 75

Write the word or phrase that best completes each statement or answers the question.
An astronaut on a strange new planet having no atmosphere finds that she can jump up to
a maximum height of 27 m when her initial upward speed is 6.0 m/s. What is the
magnitude of the acceleration due to gravity on the planet?

Question 76

Write the word or phrase that best completes each statement or answers the question.
A foul ball is hit straight up into the air with a speed of 30 m/s, and air resistance is
negligible.
(a) Calculate the time required for the ball to rise to its maximum height.
(b) Calculate the maximum height reached by the ball above the point where it hit the bat.
(c) Determine the times at which the ball passes a point 25 m above the point where it was
hit by the bat.
(d) Explain why there are two answers to part (c).

Question 77

Choose the one alternative that best completes the statement or answers the question.
Car A is traveling at 22.0 m/s and car B at 29.0 m/s. Car A is 300 m behind car B when the driver of car A accelerates his car with a uniform forward acceleration of
How long after car A begins to accelerate does it take car A to overtake car B ?

A) 5.50 s
B) 19.0 s
C) 316 s
D) 12.6 s
E) Car A never overtakes car B.

Question 78

Choose the one alternative that best completes the statement or answers the question.
A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.0 s, assuming negligible air resistance?

A) 19.6 m/s downward
B) 0 m/s
C) 9.8 m/s upward
D) 9.8 m/s downward

Question 79

Choose the one alternative that best completes the statement or answers the question.
A car is traveling at 26.0 m/s when the driver suddenly applies the brakes, causing the car to slow down with constant acceleration. The car comes to a stop in a distance of 120 m. How fast was the car moving when it was 60.0 m past the point where the brakes were applied?

A) 22.5 m/s
B) 12.1 m/s
C) 15.0 m/s
D) 18.4 m/s
E) 9.20 m/s

Question 80

Choose the one alternative that best completes the statement or answers the question.
A ball is projected upward at time t = 0 s, from a point on a flat roof 10 m above the ground. The ball rises and then falls with insignificant air resistance, missing the roof, and strikes the ground.
The initial velocity of the ball is 58.5 m/s. Consider all quantities as positive in the upward
Direction. At time t = 5.97 s, the vertical velocity of the ball is closest to

A) 0 m/s.
B) +12 m/s.
C) -12 m/s.
D) -175 m/s.
E) +175 m/s.