A kangaroo can move at 40 miles per hour. How fast is this in m/s? (Note: 1 mile = 1.6 km)
The correct answer and explanation is:
Let’s start by converting the kangaroo’s speed from miles per hour (mph) to meters per second (m/s).
Given:
- Speed = 40 miles per hour (mph)
- 1 mile = 1.6 kilometers (km)
- 1 kilometer = 1000 meters (m)
- 1 hour = 3600 seconds (s)
Step 1: Convert miles to kilometers
Since 1 mile = 1.6 km,
40 miles = 40 × 1.6 = 64 kilometers
Step 2: Convert kilometers to meters
1 km = 1000 m,
So, 64 km = 64 × 1000 = 64,000 meters
Step 3: Convert hours to seconds
1 hour = 3600 seconds
Step 4: Calculate speed in meters per second
Speed in m/s = Total meters / Total seconds
= 64,000 meters / 3600 seconds
≈ 17.78 m/s
Final answer:
The kangaroo’s speed of 40 mph is approximately 17.78 meters per second (m/s).
Explanation:
Converting units is crucial when comparing or combining measurements in different systems. The problem asks us to convert speed from miles per hour (imperial system) to meters per second (metric system), which is more standard in science and many countries.
First, knowing that 1 mile equals 1.6 kilometers allows us to change the distance units from miles to kilometers, which are easier to convert to meters since 1 km = 1000 m. This conversion is a direct multiplication.
Next, converting time units from hours to seconds is essential because speed in meters per second requires time in seconds. There are 3600 seconds in one hour (60 minutes × 60 seconds).
Finally, dividing the total distance in meters by the total time in seconds gives the speed in meters per second.
This step-by-step conversion helps avoid mistakes and ensures clarity. The calculated speed (about 17.78 m/s) is reasonable for a fast-moving kangaroo, considering that 40 mph is a high speed for animals.