Exercise 8.4

1. Convert the following speeds into [tex]m/s[/tex]:
a. [tex]72 \, km/h[/tex]
b. [tex]108 \, km/h[/tex]
c. [tex]900 \, km/h[/tex]

2. Convert the following speeds into [tex]km/h[/tex]:
a. [tex]25 \, m/s[/tex]
b. [tex]45 \, m/s[/tex]
c. [tex]15 \, m/s[/tex]

3. An airplane is flying at a speed of [tex]625 \, km/h[/tex].
a. If the distance between two cities is [tex]1250 \, km[/tex], find the time taken to reach the destination by the airplane.
b. How much distance is covered in 45 minutes?
c. How much distance is covered in 15 seconds?

Sure! Let's go through the solution step-by-step:

1. Convert the units of speeds from kilometers per hour (km/h) to meters per second (m/s):

a. For 72 km/h:

72 km/h is equivalent to 20.0 m/s.

b. For 108 km/h:

108 km/h is equivalent to 30.0 m/s.

c. For 900 km/h:

900 km/h is equivalent to 250.0 m/s.

2. Convert the units of speeds from meters per second (m/s) to kilometers per hour (km/h):

a. For 25 m/s:

25 m/s is equivalent to 90.0 km/h.

b. For 45 m/s:

45 m/s is equivalent to 162.0 km/h.

c. For 15 m/s:

15 m/s is equivalent to 54.0 km/h.

3. Determine the time taken by an aeroplane traveling at 625 km/h to cover a distance of 1250 km:

The time taken is 2.0 hours.

4. Calculate the distance covered by the aeroplane in 45 minutes:

In 45 minutes, the aeroplane covers a distance of 468.75 kilometers.

5. Calculate the distance covered by the aeroplane in 15 seconds:

In 15 seconds, the aeroplane covers a distance of approximately 2.604 kilometers.

These are the detailed steps and solutions for converting speeds and calculating time and distance for the aeroplane.