Exam
Name _________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which one of the following is an example of a vector quantity?
A) mass
B) area
C) distance
1)
D) velocity
2) Which of the following operations will not change a vector?
2)
A) Rotate it.
B) Multiply it by a constant factor.
C) Add a constant vector to it.
D) Translate it parallel to itself.
3) Ignoring air resistance, the horizontal component of a projectile's velocity
A) is zero.
B) continuously decreases.
C) continuously increases.
D) remains constant.
3)
4) A ball is thrown with a velocity of 20 m/s at an angle of 60° above the horizontal. What is the
horizontal component of its instantaneous velocity at the exact top of its trajectory?
A) 17 m/s
B) 20 m/s
C) 10 m/s
4)
D) zero
5) Ignoring air resistance, the horizontal component of a projectile's acceleration
A) continuously increases.
B) continuously decreases.
C) remains a non-zero constant.
D) is zero.
5)
6) A soccer ball is kicked with a velocity of 25 m /s at an angle of 45° above the horizontal. What is the
vertical component of its acceleration as it travels along its trajectory?
A) (9.80 m/s2) x sin (45°) downward
B) (9.80 m/s2) x sin (45°) upward
C) (9.80 m /s2) upward
D) 9.80 m /s2 downward
7) If the acceleration vector of an object is directed anti-parallel to the velocity vector,
6)
7)
A) the object is turning.
B) the object is moving in the negative x-direction.
C) the object is slowing down.
D) the object is speeding up.
8) At what angle should a water-gun be aimed in order for the water to land with the greatest
horizontal range?
A)0°
B)30°
C)60°
D)45°
9) An Olympic athlete throws a javelin at four different angles above the horizontal, each with the
same speed: 30°, 40°, 60°, and 80°. Which two throws cause the javelin to land the same distance
away?
A) 30° and 60°
B) 40° and 60°
C) 40° and 80°
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8)
D) 30° and 80°
9)
10) A ball is thrown at an original speed of 8.0 m /s at an angle of 35° above the horizontal. What is the
speed of the ball when it returns to the same horizontal level?
A)16m/s
B)8.0m/s
C)4.0m/s
D)9.8m/s
10)
11) When a football in a field goal attempt reaches its maximum height, how does its speed compare to
its initial speed?
A) It is greater than its initial speed.
B) It is equal to its initial speed.
C) It is zero.
D) It is less than its initial speed.
11)
12) A bullet is fired horizontally, and at the same instant a second bullet is dropped from the same
height. Ignore air resistance. Compare the times of fall of the two bullets.
A) They hit at the same time.
B) The fired bullet hits first.
C) The dropped bullet hits first.
D) cannot tell without knowing the masses
12)
13) A plane flying horizontally at a speed of 50.0 m/s and at an elevation of 160 m drops a package.
Two seconds later it drops a second package. How far apart will the two packages land on the
ground?
A) 162 m
B)177m
C) 100 m
D) 283 m
13)
14) The acceleration of gravity on the Moon is only one-sixth of that on Earth. If you hit a baseball on
the Moon with the same effort (and at the speed and angle) that you would on Earth, the ball
would land
A) the same distance away.
B) 36 times as far.
C) 6 times as far.
D) one-sixth as far.
14)
15) A pilot drops a water balloon from a plane flying horizontally at a constant speed. Neglecting air
resistance, when the water balloon hits the ground the horizontal location of the plane will
A) be behind the bomb.
B) depend on the speed of the plane when the bomb was released.
C) be in front of the bomb.
D) be over the bomb.
15)
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Answer Key
Testname: CH 3 QUESTIONS MC
1) D
2) D
3) D
4)C
5) D
6) D
7) C
8) D
9) A
10) B
11) D
12) A
13) C
14) C
15) D
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