Section 2.4
How Fast?
Practice Test
1.
A bicycle rider travels 15 km in 1.25 hours. What is the rider's average speed?
a.
10.5 km/h
b.
22.5 km/h
c.
12 km/h
d.
13.75 km/h
Hint
2.
Based on the graph of Figure 2-21, what is the object's velocity at
t
= 4 s?
a.
-5 m/s
b.
4 m/s
c.
0 m/s
d.
5 m/s
Hint
3.
If a runner maintains a constant speed of 12.0 km/h, how long will it take him to complete a marathon race of 26.2 miles?
a.
2.18 h
b.
3.52 h
c.
5.32 h
d.
3.14 h
Hint
4.
The magnitude of velocity is __________.
a.
distance
b.
direction
c.
speed
d.
acceleration
Hint
5.
In Figure 2-20, if the blue jogger were ahead of the red jogger at
t
= 0 s, but they both had the same velocities as in the text, how (if at all) would the graph change?
a.
The slopes of the lines would remain the same, but the blue jogger's line would cross the
y
-axis above zero.
b.
The lines would still cross at zero, but the slope of the blue jogger's line would be steeper.
c.
The labels on the lines would be reversed.
d.
There would be no change.
Hint
6.
Which of the following equations can be used to find the position of an object moving at constant velocity?
a.
d
=
d
f
+
vt
b.
Δd =
d
f
-
d
i
c.
d
=
d
f
-
vt
d.
tan θ =
R
y
/
R
x
Hint
7.
You drive a car for 3.0 h at 97 km/h, then for another 3.0 h at 72 km/h. What is your average velocity?
a.
85 m/s
2
b.
-85 km/h
c.
85 km/h
d.
85 km/h
2
Hint
8.
You are at a friend's house who lives 10 km north of your house. You drive north from there at a constant speed of 35 mph toward the pizza shop and arrive there 10 minutes later to pick up your pizza. How far from your house are you?
a.
10 km
b.
20 km
c.
31 km
d.
20 m
Hint
9.
You and a friend leave school at the same time. You drive at a constant 55 km/h and your friend drives 7.0×10
1
km/h. How long does it take each car to reach a mall that is 25 km from the school?
a.
you: 1 hour 40 minutes, your friend 36 minutes
b.
you: 2.2 hours, your friend: 2.8 hours
c.
you: 22 minutes, your friend: 27 minutes
d.
you: 27 minutes, your friend: 22 minutes
Hint
10.
Looking at Figure 2-20, at what time would the first picture of the joggers be most likely to have occurred?
a.
1 s
b.
-1 s
c.
0 s
d.
it cannot be determined from the given information
Hint
11.
You and a friend each walk 8.0 km. You walk at 6.4 km/h; your friend walks 8.1 km/h. How long will your friend wait for you at the end of the walk?
a.
15 minutes
b.
0.5 h
c.
30 minutes
d.
1.7 h
Hint
12.
The __________ is the ratio of the total distance traveled to the time interval.
a.
displacement
b.
instantaneous velocity
c.
acceleration
d.
average speed
Hint
13.
The slope of the line tangent to the curve on a position-time graph at a specific time is the __________.
a.
instantaneous velocity
b.
average velocity
c.
displacement
d.
instantaneous acceleration
Hint
14.
Based on the graph of Figure 2-21, where would the object be at
t
= 7 s?
a.
- 7 meters
b.
-15 meters
c.
- 10 meters
d.
15 meters
Hint
15.
You drive a car for 2.0 h at 60 km/h, then for another 3.0 h at 85 km/h. What is your average velocity?
a.
73 km/h
b.
- 73 km/h
c.
75 km/h
d.
75 km/h
2
Hint
