Exam 1, PHYS 201, 08F

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Name: ________________________ Class: ___________________ Date: __________
Exam 1, PHYS 201, 08F
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
____
1. Which of these is the standard for the kilogram?
a. a fraction of the mass of the Earth
c. the mass of 3x108 photons
b. the mass of a billion billion Cesium
d. the mass of a particular platinum-iridium
atoms
cylinder
3
2. The volume of a room is 1000 m . What is the volume in cubic centimeters?
____
a. 1x10-3 cm3
d. 1x1012 cm3
b. 10 cm3
e. 1x105 cm3
9
3
c. 1x10 cm
3. In this graph, what is the instantaneous acceleration at point C?
a.
b.
c.
1 m/s2
-1 m/s2
-2 m/s2
d.
e.
1
2 m/s2
none of these
ID: A
Name: ________________________
____
____
4. In the previous graph, what is the average acceleration between points A and C?
d. -2 m/s2
a. 0.4 m/s2
2
b. 1 m/s
e. Not enough information
c. 0.33 m/s2
5. You throw a very bouncy ball toward the ground; it bounces off the ground and returns to your hand at the
same speed at which you threw it.. Which of these plots best describes the motion of the ball from the
moment you release it to the moment you catch it?
a.
____
ID: A
c.
b.
d.
6. You throw a ball upwards with an initial velocity of 20 m/s. How high does the ball go?
a.
b.
10 m
20 m
c.
d.
2
60 m
40 m
Name: ________________________
____
7. This figure shows the vectors A and B. What is the resultant vector of A-B?
a.
____
ID: A
c.
b.
d.
8. While exploring a cave a spelunker starts at the entrance and moves the following distances: 30.0 m west,
20.0 m at an angle 40.0° north of east, and 100. m south. What is the magnitude of his resultant
displacement?
a.
b.
150. m
122 m
c.
d.
3
102 m
88.3 m
Name: ________________________
____
ID: A
9. A guy walks 10 meters towards the North. Then, he walks 5 meters to the east. What is the angle of his
displacement?
c. 84° Ε of N
a. 79° S of Ε
d. 63° Ν of Ε
b. 27° Ν of Ε
____ 10. Which of these statements about the motion of a projectile is/are true?
I. The x-component of the velocity does not change.
II. The y-component of the velocity increases throughout the trajectory.
III. The x-component of the acceleration is zero.
IV. The maximum height is dependent on the x-component of the velocity
V. The maximum range is dependent only on the x-component of the velocity.
a.
b.
c.
III
d.
I & III
e.
I, III, & V
ä has components A and A . If || A || >
____ 11. The vector A
x
x
y
II & IV
All are true
| A | (that is, the magnitude of the x-component is greater
| y|
A?
than the magnitude of the y-component), which of these is a possible angle for ä
I. 60º above the positive x-axis
II. 30º above the positive x-axis
III. 40º below the negative x-axis
IV. 45º below the positive x-axis
a. II, III, & IV
d. IV
b. I
e. II
c. II & III
____ 12. A ferris wheel has a radius of 20 m and makes 10 revolutions per minute. What is the magnitude of the
centripetal acceleration on a person at the top of the ferris wheel?
a.
b.
20 m/s2
3x107 m/s2
c.
d.
4
200 m/s2
the ferris wheel is turning at a constant
speed, so the acceleration is zero
Name: ________________________
ID: A
____ 13. The centripetal acceleration of an object points in which direction?
a. in the direction of motion
c. in the same direction as the velocity
b. towards the center of the circular path
d. not enough information
____ 14. The following is the function for the position of a particle:
x = 3t 2 8i − 5t 3 8j + (3t − 4)k8
What is the magnitude of the acceleration at t=1 second?
c.
a. 6 m/s2
2
b. 15 m/s
d.
____ 15. Which of these is the definition of acceleration?
-9 m/s2
30 m/s2
d2x
dt 2
dx
II.
dt
dv
III.
dt
speed
IV.
time
I.
a.
b.
c.
I
IV
I & III
d.
e.
5
II
I, III, & IV
Name: ________________________
ID: A
Problem
16. Derive these equations using methods of differential calculus.
v = v 0 + at
1
x = x 0 + v 0 t + 2 at 2
-
6
Name: ________________________
ID: A
17. In this figure, a stone is projected at a cliff of height, h, with an initial speed of 30.0 m/s directed at angle
θ0=50° above the horizontal. The stone strikes at A, 2.0 seconds after launching. Find the following:
a) The height of the cliff
b) the speed of the stone just before impact at A
c) the maximum height H above the ground
-
7
Name: ________________________
ID: A
18. The position ä
x of a particle moving in the xy plane is given by ä
x = (2t 3 − 2t 4 )i8 + (t 2 − 3t)j8, with ä
x in m and
t>0s.
a) What is the acceleration, in vector notation, when t=2.0 s?
b) What is the magnitude of the acceleration at t=2.0s?
c) When (if ever) is the velocity zero?
d) What is the x-coordinate when the particle is at its maximum y-coordinate?
-
8
ID: A
Exam 1, PHYS 201, 08F
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
HW
D
C
C
A
A
B
C
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
PTS: 1
8. ANS: D
HW
9.
10.
11.
12.
13.
14.
15.
PTS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
1
D
B
C
A
B
D
C
PROBLEM
16. ANS:
Derivation
PTS: 1
17. ANS:
??
PTS: 1
18. ANS:
??
PTS: 1
1
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