1.The fastest fish, the sailfish, can swim 1.2 × 102 km/h. Suppose you have

a friend who lives on an island 16 km away from the shore. If you send

a message using a sailfish as a messenger, how long will it take for the

message to reach your friend?

2. The Sears Tower in Chicago is 443 m tall. Joe wants to set the world’s

stair climbing record and runs all the way to the roof of the tower. If Joe’s

average upward speed is 0.60 m/s, how long will it take Joe to climb from

street level to the roof of the Sears Tower?

3. An ostrich can run at speeds of up to 72 km/h. How long will it take an

ostrich to run 1.5 km at this top speed?

4. A cheetah is known to be the fastest mammal on Earth, at least for short

runs. Cheetahs have been observed running a distance of 5.50 × 102 m

with an average speed of 1.00 × 102 km/h.

a. How long would it take a cheetah to cover this distance at this speed?

b. Suppose the average speed of the cheetah were just 85.0 km/h.

What distance would the cheetah cover during the same time interval

calculated in (a)?

4. A pronghorn antelope has been observed to run with a top speed of

97 km/h. Suppose an antelope runs 1.5 km with an average speed of

85 km/h, and then runs 0.80 km with an average speed of 67 km/h.

a. How long will it take the antelope to run the entire 2.3 km?

b. What is the antelope’s average speed during this time?

5. Jupiter, the largest planet in the solar system, has an equatorial radius of

about 7.1 × 104 km (more than 10 times that of Earth). Its period of rotation,

however, is only 9 h, 50 min. That means that every point on

Jupiter’s equator “goes around the planet” in that interval of time. Calculate

the average speed (in m/s) of an equatorial point during one period

of Jupiter’s rotation. Is the average velocity different from the average

speed in this case?

6. The peregrine falcon is the fastest of flying birds (and, as a matter of fact,

is the fastest living creature). A falcon can fly 1.73 km downward in 25 s.

What is the average velocity of a peregrine falcon?

7. The black mamba is one of the world’s most poisonous snakes, and with

a maximum speed of 18.0 km/h, it is also the fastest. Suppose a mamba

waiting in a hide-out sees prey and begins slithering toward it with a

velocity of +18.0 km/h. After 2.50 s, the mamba realizes that its prey can

move faster than it can. The snake then turns around and slowly returns

to its hide-out in 12.0 s. Calculate

a. the mamba’s average velocity during its return to the hideout.

b. the mamba’s average velocity for the complete trip.

c. the mamba’s average speed for the complete trip.

8. In the Netherlands, there is an annual ice-skating race called the “Tour of

the Eleven Towns.” The total distance of the course is 2.00 × 102 km, and

the record time for covering it is 5 h, 40 min, 37 s.

a. Calculate the average speed of the record race.

b. If the first half of the distance is covered by a skater moving with

a speed of 1.05v, where v is the average speed found in (a), how

long will it take to skate the first half? Express your answer in hours

and minutes.