a.
108 m/s and 10.8
g
b.
108 m/s and 11.1
g
c.
111 m/s and 10.8
g
d.
111 m/s and 11.1
g
The speed of propagation of the action potential (an electrical signal) in a nerve cell depends (inversely)
on the diameter of the axon (nerve fiber). If the nerve cell connecting the spinal cord to your feet is 1.1 m
long, and the nerve impulse speed is 18 m/s, how long (in seconds) does it take for the nerve signal to
travel this distance?
The North American and European continents are moving apart at a rate of about 3 cm/y. At this rate how
long will it take them to drift 500 km farther apart than they are at present?
A commuter backs her car out of her garage with an acceleration of 1.40 m/s
2
. (a) How long (in seconds)
does it take her to reach a speed of 2.00 m/s?
1.43 s
A student drove to the university from her home and noted that the odometer reading of her car increased
by 12.0 km. The trip took 18.0 min. (a) What was her average speed? (b) If the straightline distance from
her home to the university is 10.3 km in a direction 25.0
o
south of east, what was her average velocity?
c.
90 km/h and 22.8 km/h 25
o
S of E
d.
90 km/h and 34.3 km/h 25
o
S of E
The average speed of an object is calculated as the total distance traveled divided by the time interval.
Rank the average speeds from lowest to highest for the following total distances traveled and time
intervals. (Note: x represents the same distance in each case, and t represents a certain time interval).

a.
b.
c.
d.
e.
x/4, 4t

a.
b.
c.
d.
e.
x, t

a.
b.
c.
d.
e.
x, 4t

a.
b.
c.
d.
e.
4x, t

a.
b.
c.
d.
e.
4x, t/4