don't answers questions 1,2,5,7,8,10,11,and 12
Abdull2004
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almalki (aa79893) – assignment3 – kumar – (1824251) 1
This print-out should have 46 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering.
001 (part 1 of 2) 10.0 points A particle moves according to the equation x = (10 m/s2) t2 where x is in meters and t is in seconds. Find the average velocity for the time in-
terval from 2.35 s to 4.01 s. Answer in units of m/s.
002 (part 2 of 2) 10.0 points Find the average velocity for the time interval from 2.35 s to 2.45 s. Answer in units of m/s.
003 (part 1 of 2) 10.0 points An acceleration (in m/s2) has the time de- pendence shown on the graph below. The particle starts from rest (v0 = 0 m/s) at the origin (x0 = 0 m).
0 1 2 3 4 5 −3
−2
−1
0
a (m
/ s2 )
t (s)
Acceleration vs Time
Find the velocity at t = 5 s.
1. v t=5
= −3
2. v t=5
= −8
3. v t=5
= −1
4. v t=5
= −6
5. v t=5
= −2 m/s
6. v t=5
= −4
004 (part 2 of 2) 10.0 points Find the position at t = 5 s.
1. x t=5
= −9 m
2. x t=5
= −8
3. x t=5
= −24
4. x t=5
= −12
5. x t=5
= −10.5
6. x t=5
= −4.5
005 (part 1 of 2) 10.0 points Throw a ball upward from point O with an initial speed of 54 m/s.
t
hA y
tB
hB
tA
b
b
b
b
b
b
b
b
b b b b b b
b b
b
b
b
b
b
b
b
b
54 m/s
O
B
A
What is the maximum height? The accel- eration of gravity is −9.8 m/s2 . Answer in units of m.
006 (part 2 of 2) 10.0 points If the speed of the ball as it passes point B is 1
2 (54 m/s) = 27 m/s, what is the height hB
of B above O? Answer in units of m.
007 (part 1 of 2) 10.0 points A stone falls from rest from the top of a cliff. A second stone is thrown downward from the same height 3 s later with an initial speed of 58.8 m/s. They hit the ground at the same time. How long does it take the first stone to hit
the ground? The acceleration of gravity is 9.8 m/s2 . Answer in units of s.
almalki (aa79893) – assignment3 – kumar – (1824251) 2
008 (part 2 of 2) 10.0 points How high is the cliff? Answer in units of m.
009 10.0 points The acceleration of a marble in a certain fluid is proportional to the speed of the marble squared, given by
a = α v2 ,
where v > 0 m/s and α = −4.64 m−1. If the marble enters this fluid with a speed
of 1.87 m/s, how long will it take before the marble’s speed is reduced to half of its initial value? Answer in units of s.
010 10.0 points A rocket sled for testing equipment under large accelerations starts at rest and acceler- ates according to the expression
a = (3.4 m/s3) t+ (2.5 m/s2) .
How far does the sled move in the time interval t = 0 to t = 0.88 s ? Answer in units of m.
011 10.0 points A body moving with uniform acceleration has a velocity of 7.15 cm/s when its x coordinate is 2.96 cm. If its x coordinate 0.874 s later is −7.66 cm,
what is the x-component of its acceleration? Answer in units of cm/s2.
012 10.0 points A car starts from rest and accelerates for 4.6 s with an acceleration of 2.6 m/s2. How far does it travel? Answer in units of m.
013 (part 1 of 2) 10.0 points An electron has an initial speed of 1.99× 105 m/s. If it undergoes an acceleration of
3.9× 1014 m/s2, how long will it take to reach a speed of 6.57× 105 m/s?
Answer in units of s.
014 (part 2 of 2) 10.0 points How far has it traveled in this time? Answer in units of m.
015 10.0 points A subway train starting from rest leaves a station with a constant acceleration. At the end of 5.85 s, it is moving at 17.433 m/s. What is the train’s displacement in the first
4.329 s of motion? Answer in units of m.
016 10.0 points At a certain instant an object is moving to the right with speed 1.0 m/s and has a constant acceleration to the left of 1.0 m/s2. At what later time will the object momen-
tarily be at rest?
1. Never; with a constant acceleration it cannot come to rest.
2. None of these
3. After 1 sec
4. After 2 sec
5. After 0.5 sec
6. After 0.1 sec
017 10.0 points Which of the following describe possible sce- narios? A) An object has zero instantaneous velocity
and non-zero acceleration. B) An object has negative acceleration and
is speeding up. C) An object has positive acceleration and
constant velocity. D) An object has positive velocity and zero
acceleration. E) An object has increasing positive posi-
tion and negative velocity. F) An object has decreasing positive posi-
tion and negative acceleration.
almalki (aa79893) – assignment3 – kumar – (1824251) 3
1. A, B, D, E, and F only.
2. A, B, C, D, and F only.
3. A, D, and F only.
4. D and F only.
5. A, D, E, and F only.
6. All are possible.
7. None are possible.
8. A, C, D, and F only.
9. B, C, and D only.
10. A, B, D, and F only.
018 10.0 points A stone is thrown straight upward and at the top of its trajectory its velocity is momentar- ily zero.
What is its acceleration at this point?
1. 9.8 m/s2 up
2. Unable to determine
3. Zero
4. 9.8 m/s2 down
019 (part 1 of 4) 10.0 points Consider the acceleration of a particle along a straight line with an initial position of 0 m
and an initial velocity of 0 m/s.
2
3
4
5
6
7
0 1 2 3 4 5 6 7 8 9 time (s)
a cc el er a ti o n (m
/ s2 )
What is the velocity at 4 s? Answer in units of m/s.
020 (part 2 of 4) 10.0 points Find the position after the first 7 s. Answer in units of m.
021 (part 3 of 4) 10.0 points How far did the particle travel from 7 s to 9 s? Answer in units of m.
022 (part 4 of 4) 10.0 points Calculate the magnitude of the particle’s av- erage velocity from 1 s to 9 s. Answer in units of m/s.
023 (part 1 of 2) 10.0 points The position versus time for a certain object moving along the x-axis is shown. The ob- ject’s initial position is −4 m.
almalki (aa79893) – assignment3 – kumar – (1824251) 4
−12
−10
−8
−6
−4
−2
0
2
4
6
8
10
0 1 2 3 4 5 6 7 8 9
b
b
b b
b
b
time (s)
p o si ti o n (m
)
Find the instantaneous velocity at 6 s. Answer in units of m/s.
024 (part 2 of 2) 10.0 points Find the average velocity over the whole time shown. Answer in units of m/s.
025 10.0 points A car travels along a straight stretch of road. It proceeds for 12 mi at 51 mi/h, then 20.5 mi at 46 mi/h, and finally 42.1 mi at 35.7 mi/h. What is the car’s average velocity during
the entire trip? Answer in units of mi/h.
026 (part 1 of 3) 10.0 points A ball is dropped from rest at point O. After falling for some time, it passes by a window of height 3.1 m and it does so in 0.41 s. The ball accelerates all the way down; let vA be its speed as it passes the window’s top A and vB its speed as it passes the window’s bottom B.
O
A
B
3.1 m
bb b
b
b
b
b
b
b
b
b
b
x
y
Howmuch did the ball speed up as it passed the window; i.e., calculate ∆vdown = vB−vA ? The acceleration of gravity is 9.8 m/s2 . Answer in units of m/s.
027 (part 2 of 3) 10.0 points Calculate the speed vA at which the ball passes the window’s top. Answer in units of m/s.
028 (part 3 of 3) 10.0 points Now consider a new situation: The ball is thrown upward from the ground with an ini- tial velocity that takes exactly the same time tBA = tAB = 0.41 s to pass by the window, with the ball moving up rather than down. Consider the ball’s slowdown during this time: Let v′B be the ball’s speed (do not confuse the speed with the velocity) as it passes the win- dow’s bottom on the way up and let v′A be its speed as it passes the window’s top, also in its way up. How does the ball’s slowdown
∆vup = v ′
B − v ′
A
compare to its speedup ∆vdown on the way down?
1. ∆vup > ∆vdown.
2. ∆vup < ∆vdown.
3. ∆vup = ∆vdown.
4. ∆vup < ∆vdown if the mass of the ball is less than 0.1 kg and ∆vup > ∆vdown if the mass of the ball is greater than 0.1 kg
5. ∆vup > ∆vdown if the mass of the ball
almalki (aa79893) – assignment3 – kumar – (1824251) 5
is less than 0.1 kg and ∆vup < ∆vdown if the mass of the ball is greater than 0.1 kg
029 10.0 points A ball is thrown straight up and reaches a maximum height in 5.36 s.
t
hA y
tB
hB
tA
b
b
b
b
b
b
b
b
b b b b b b
b b
b
b
b
b
b
b
b
b
v0
O
B
A
What was its initial speed? The accelera- tion of gravity is 9.8 m/s2 . Answer in units of m/s.
030 10.0 points A train is moving parallel and adjacent to a highway with a constant speed of 29 m/s. Ini- tially a car is 36 m behind the train, traveling in the same direction as the train at 43 m/s and accelerating at 4 m/s2. What is the speed of the car just as it passes
the train? Answer in units of m/s.
031 10.0 points The position-versus-time graph below de- scribes the motion of three different bodies (labeled 1, 2, 3).
1 2 3
x B
x A
t A
t B
x
t
A
B
Consider the average velocities of the three bodies. Which of the following statements is
correct?
1. v̄1 > v̄2 > v̄3
2. v̄1 > v̄2 and v̄3 > v̄2
3. v̄1 = v̄2 = v̄3
4. v̄1 < v̄2 < v̄3
032 (part 1 of 3) 10.0 points A particle moving uniformly along the x axis is located at 15.2 m at 1.61 s and at 3.05 m at 3.06 s. Find its displacement during this time in-
terval. Answer in units of m.
033 (part 2 of 3) 10.0 points What is its average velocity during this time interval? Answer in units of m/s.
034 (part 3 of 3) 10.0 points Calculate the particle’s average speed during this time interval. Answer in units of m/s.
035 (part 1 of 3) 10.0 points Consider the following graph of motion.
0 1 2 3 4 0
10
20
30
Time (hr)
D is
ta nc
e (k
m )
What distance was covered in the first 3 hours?
1. 10 km
2. 25 km
3. 30 km
4. 5 km
5. 15 km
almalki (aa79893) – assignment3 – kumar – (1824251) 6
6. 20 km
036 (part 2 of 3) 10.0 points The graph indicates
1. constant velocity.
2. no acceleration.
3. changing velocity.
4. no motion.
5. constant position.
037 (part 3 of 3) 10.0 points Consider the following graph of motion.
0 1 2 3 4 5 6 7 8 9 0
50
100
150
200
250
300
350
400
Time (sec)
D is
ta nc
e (m
)
The distance is
1. constant.
2. increasing.
3. decreasing.
038 10.0 points A student drops a rock from a bridge to the water 11.2 m below. With what speed does the rock strike
the water? The acceleration of gravity is 9.8 m/s2 . Answer in units of m/s.
039 (part 1 of 3) 10.0 points A model rocket is launched straight upward with an initial speed of 45.8 m/s. It acceler- ates with a constant upward acceleration of 2.09 m/s2 until its engines stop at an altitude
of 190 m. What is the maximum height reached by
the rocket? The acceleration of gravity is 9.81 m/s2. Answer in units of m.
040 (part 2 of 3) 10.0 points When does the rocket reach maximum height? Answer in units of s.
041 (part 3 of 3) 10.0 points How long is the rocket in the air? Answer in units of s.
042 10.0 points In order to qualify for the finals in a racing event, a race car must achieve an average speed of 258 km/h on a track with a total length of 1420 m. If a particular car covers the first half of the
track at an average speed of 225 km/h, what minimum average speed must it have in the second half of the event in order to qualify? Answer in units of km/h.
043 (part 1 of 2) 10.0 points A racing car reaches a speed of 44 m/s. At this instant, it begins a uniform deceleration using a parachute and a braking system, and comes to rest 3.5 s later. Find the acceleration of the car. Answer in units of m/s2.
044 (part 2 of 2) 10.0 points How far does the car travel after the accelera- tion starts? Answer in units of m.
045 (part 1 of 2) 10.0 points In the time interval from 0 s to 15 s, the acceleration of a particle is given by a = (0.4 m/s3) t for one-dimensional motion. If a particle starts from rest at the ori-
gin, calculate its instantaneous velocity at any time during the interval 4 s to 10 s.
1. v(t) = (0.45 m/s3) t2
2. v(t) = (0.4 m/s3) t2
almalki (aa79893) – assignment3 – kumar – (1824251) 7
3. v(t) = (0.9 m/s3) t2
4. v(t) = (0.2 m/s3) t2
046 (part 2 of 2) 10.0 points Calculate its average velocity over the time interval from 11 s to 15 s. Answer in units of m/s.
