Projectile Multiple Choice
For each question below, think about each answer. Determine whether or not it correctly describes
some aspect of projectile motion.
Which of the following statements are true of the horizontal motion of projectiles? List all that apply.
a. A projectile does not have a horizontal velocity.
b. A projectile with a rightward component of motion will have a rightward component of
acceleration.
c. The horizontal velocity of a projectile changes by 9.8 m/s each second.
d. A projectile with a horizontal component of motion will have a constant horizontal
velocity.
e. The horizontal velocity of a projectile is 0 m/s at the peak of its trajectory.
f. The horizontal velocity of a projectile is unaffected by the vertical velocity; these two
components of motion are independent of each other.
g. The horizontal displacement of a projectile is dependent upon the time of flight and the
initial horizontal velocity.
h. The final horizontal velocity of a projectile is always equal to the initial horizontal
velocity.
i. As a projectile rises towards the peak of its trajectory, the horizontal velocity will
decrease; as it falls from the peak of its trajectory, its horizontal velocity will decrease.
j. Consider a projectile launched from ground level at a fixed launch speed and a variable
angle and landing at ground level. The horizontal displacement (i.e., the range) of the
projectile will always increase as the angle of launch is increased from 0 degrees to 90 degrees.
k. Consider a projectile launched from ground level at a fixed launch angle and a variable
launch speed and landing at ground level. The horizontal displacement (i.e., the range) of the
projectile will always increase as the launch speed is increased
Which of the following statements are true of the vertical motion of projectiles? List all that apply.
a. The vertical component of a projectile's velocity is a constant value of 9.8 m/s.
b. The vertical component of a projectile's velocity is constant.
c. The vertical component of a projectile's velocity is changing.
d. The vertical component of a projectile's velocity is changing at a constant rate.
e. A projectile with an upward component of motion will have a upward component of
acceleration.
f. A projectile with an downward component of motion will have a downward component of
acceleration.
g. The magnitude of the vertical velocity of a projectile changes by 9.8 m/s each second.
h. The vertical velocity of a projectile is 0 m/s at the peak of its trajectory.
i. The vertical velocity of a projectile is unaffected by the horizontal velocity; these two
components of motion are independent of each other.
j. The final vertical velocity of a projectile is always equal to the initial vertical velocity.
k. The vertical acceleration of a projectile is 0 m/s/s when it is at the peak of its trajectory.
l. As a projectile rises towards the peak of its trajectory, the vertical acceleration will
decrease; as it falls from the peak of its trajectory, its vertical acceleration will decrease.
m. As a projectile rises towards the peak of its trajectory, the vertical acceleration is directed
upward; as it falls from the peak of its trajectory, its vertical acceleration is directed downward.
n. The peak height to which a projectile rises above the launch location is dependent upon
the initial vertical velocity.
o. As a projectile rises towards the peak of its trajectory, the vertical velocity will decrease;
as it falls from the peak of its trajectory, its vertical velocity will decrease.
p. Consider a projectile launched from ground level at a fixed launch speed and a variable
angle and landing at ground level. The vertical displacement of the projectile during the first
half of its trajectory (i.e., the peak height) will always increase as the angle of launch is
increased from 0 degrees to 90 degrees.
q. Consider a projectile launched from ground level at a fixed launch angle and a variable
launch speed and landing at ground level. The vertical displacement of the projectile during the
first half of its trajectory (i.e., the peak height) will always increase as the launch speed is
increased.
Which of the following statements are true of the time of flight for a projectile? List all that apply.
a. The time that a projectile is in the air is dependent upon the horizontal component of the
initial velocity.
b. The time that a projectile is in the air is dependent upon the vertical component of the
initial velocity.
c. For a projectile which lands at the same height that it is projected from, the time to rise to
the peak is equal to the time to fall from its peak to the original height.
d. For the same upward launch angles, projectiles will stay in the air longer if the initial
velocity is increased.
e. Assume that a kicked ball in football is a projectile. If the ball takes 3 seconds to rise to
the peak of its trajectory, then it will take 6 seconds to fall from the peak of its trajectory to the
ground
More Multiple Choice Practice
1. A baseball is thrown horizontally from a cliff. At the same instant, a bowling ball is dropped from the same height.
Assuming air resistance can be ignored, which of the following statements is correct?
a. The bowling ball hits the ground first
b. Both the bowling ball and the baseball hit the ground at the same time.
c. The baseball has the greater acceleration just before it hit the ground
d. The bowling ball has the greater velocity just before it hit the ground
e. The bowling ball has the greater acceleration just before it hit the ground
2. A ball is rolled off the edge of a horizontal table. The ball has an initial speed v o and lands on the floor some
distance from the base of the table. Which of the following statements concerning the fall of the ball is false?
a. the time of the flight depends upon the height of the table
b. one of the components of the final velocity will be vo
c. the ball will accelerate
d. the ball will have a longer flight time if vo is increased
e. the ball falls due to the force of gravity
3. If air resistance can be neglected, what happens to the horizontal velocity of a basketball as it is thrown to the basket
from the free-throw line?
a. increases
b. decreases
c. increases while the ball is going up, and then decreases while the ball is coming down
d. decreases while the ball is going up, and then increases while the ball is coming down
e. stays constant
4. Which of the following statements are true of scalars and vectors? List all that are TRUE.
a. A vector quantity always has a direction associated with it.
b. A scalar quantity can have a direction associated with it.
c. Vectors can be added together; scalar quantities cannot.
d. Vectors can be represented by an arrow on a scaled diagram; the length of the arrow represents the vector's
magnitude and the direction it points represents the vector's direction.
5. Which of the following descriptions of moving objects accurately portray a projectile? List all that apply.
a.
an object which is moving through the air and not touching any surface
b. a falling skydiver with an open parachute
c.
any object upon which air resistance is negligible
d. a free-falling object
e.
an object upon which the only significant force is the force of gravity
f.
a thrown snowball
g. a falling feather
h. a basketball tossed toward the basket
6. Which of the following statements are true of projectiles? List all that apply.
a.
A projectile is a free-falling object.
b. A projectile experiences negligible or no air resistance.
c.
A projectile must be moving in the downward direction.
d. A projectile must be accelerating in the downward direction.
e.
A projectile does not have to have horizontal motion.
f.
A projectile could begin its projectile motion with a downward velocity.
g. A projectile does not need to be "falling."
Projectile Motion Review
1. A very tall basketball player shoots a jump shot. The launch angle is +75.0°, and the total hang
time is 3.0 seconds. Assume that the launch height and hoop height are the same.
What was the launch speed?
What is the range?
2. A bowling ball rolls off of a 1.25 meter tall table. It hits the ground 1.75 meters from the edge of
the table.
What was the launch speed?
What was the time in flight?
What was the impact velocity?
What was the velocity in-flight, 0.15 s after launch?
3. A student is riding a roller coaster, while eating an ice cream cone. The roller coaster is going
up a uniform incline of +30.0° at a speed of 25 m/s. When 25.0 meters above the ground, the
student releases the ice cream cone over the side of the car. Assuming perfect projectile motion:
What is the range of the ice cream cone?
What is the total time in flight?
What is the maximum height?
What is its impact velocity?
4. A projectile is in perfect-parabola motion. It has an initial velocity of Vo at an angle of θo ,
above the horizontal.
It reaches the highest point of the arc, hmax at time “t”. It has gone a horizontal distance “d”
at the maximum height.
All of the following are true except;
a) t = (Vo cos θo ) / g
b) hmax = (Vo sinθo )2 / 2g
c) d = Vo t cosϴo
d) Vhor = Vo cosϴo