Vectors and Projectile Motion Test
Name: _______________________________
Directions: Show ALL work for full credit on free response.. Round all answers to the correct number of significant digits.
Part 1 – Multiple Choice
[2pts each]
Identify the choice that best completes the statement or answers the question.
____
1.
2.
3.
4.
5.
1.
Which of the following is an example of a vector quantity?
a. velocity
c. volume
b. temperature
d. mass
____
2.
Identify the following quantities as scalar or vector: the mass of an object, the number of leaves
on a tree, wind velocity.
a. vector, scalar, scalar
c. scalar, vector, scalar
b. scalar, scalar, vector
d. vector, scalar, vector
____
5.
For the winter, a duck flies 10.0 m/s due south against a gust of wind with a speed of 2.5 m/s.
What is the resultant velocity of the duck?
a.
12.5 m/s south
c. 7.5 m/s south
b. –12.5 m/s south
d. –7.5 m/s south
6.
____ 6. How many displacement vectors shown in the figure
to the left have horizontal components?
a. 2
c. 4
b. 3
d. 5
____ 7. Which displacement vectors shown in the figure to
the left have vertical components that are equal?
a. d and d
c. d and d
b. d and d
d. d and d
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
____ 8.
Which of the following is not an example of projectile motion?
a. a volleyball served over a net
c. a hot-air balloon drifting toward Earth
b. a baseball hit by a bat
d. a long jumper in action
____ 9.
What is the path of a projectile (in the absence of friction)?
a. a wavy line
b. a parabola
c. a hyperbola
d. Projectiles do not follow a predictable path.
57.
58.
a.
_____ 10. The vector addition of two forces of 7 N and 10 N may have _____.
a. a value greater than 17 N
b. a value less than 3 N
c. a zero value
d. any value from 3 N to 17 N
11. A ball rolls off a horizontal table with velocity v. It lands on the ground a time T later at a distance D from the
foot of the table as shown in the diagram below. Air resistance is negligible. A second heavier ball rolls off
the table with velocity v. Which one of the following is correct for the heavier ball?
Time to land
Distance from table
A.
T
D
B.
T
less than D
C.
less than T
D
D.
less than T
less than D
v
table
D
X
Y
12. Two identical metal spheres X and Y are released at the same
time from the same height above the horizontal ground.
Sphere X falls vertically from rest. Sphere Y is projected
horizontally as shown below.
Air resistance is negligible.
Which of the following statements is correct?
ground
A.
Sphere X hits the ground before sphere Y because it
travels a shorter distance.
B.
Sphere Y hits the ground before sphere X because its initial velocity is greater.
C.
The spheres hit the ground at the same time because horizontal motion does not affect vertical motion.
D.
The spheres hit the ground at the same time because they have equal weights.
13. A projectile is fired from the ground at time t = 0. It lands back on the ground at time t = T. Which of the
following sketch graphs best shows the
B.
A.
VH
VH
variation with time t of the vertical speed VV speed
speed
and horizontal speed VH of the projectile?
Air resistance is negligible.
VV
VV
0
0
T
0
t
0
T
t
T
t
D.
C.
speed
speed
VH
VV
0
0
VH
T
t
0
0
VV
Part 2 – Free Response
1. Determine the horizontal component of the 7N vector in the diagram to the
right. Round your answer to the nearest hundredth. [2pts]
2. The diagram to the right represents forces acting on an object. In which
general direction is the resultant force: [2pts]
a. North East
b. North West
c. South West
d. South East
3. A duck waddles 2.5 m east and 6.0 m north and then south-east (45o) for 4.0m. What are the magnitude and
direction of the duck’s displacement with respect to its original position? [4pts]
4. A model rocket flies horizontally off the edge of a cliff at a velocity of 50.0 m/s. The canyon below is 100.0 m
deep. (a = g = 9.81 m/s ) [ 8pts]
5.
a. How far from the edge of the cliff does the model rocket land?
b. With what velocity does it hit the ground?
5. A ball is projected from ground level with a speed of 28 m s–1 at an angle of 30 to the horizontal as shown
below.
30
wall
h
16m
There is a wall of height h at a distance of 16 m from the point of projection of the ball. Air resistance is
negligible.
(a) Calculate the initial magnitudes of
(i) the horizontal velocity of the ball; [2pts]
(ii) the vertical velocity of the ball. [2pts]
(b) The ball just passes over the wall. Determine the maximum height of the wall.
6. A fox sees a piece of food being thrown from a hawk’s nest and rushes to snatch it. The nest is 14.0 m high,
and the food is thrown with a horizontal velocity of 1.5 m/s. The fox is 7.0 m from the base of the tree. What is
the magnitude of the fox’s average velocity if it starts running at the moment it leaves the nest and grabs the food
in its mouth just as it touches the ground? (Assume no air resistance and that a = g = 9.81 m/s .)
a. Draw a picture representing what is known to the right. [2pts]
b. Solve the problem (find the fox’s average velocity). [ 3pts] Show all work for partial credit!