Answer:
You must travel at an average speed of 67.06 m/s to be on time to the lecture.
Explanation:
From the question, the total distance from your house to the science lecture is 75 miles.
Also, you get halfway there before you stop for a gas, that is, you have covered half of 75 miles, which 37.5 miles and you also have to cover 37.5 miles to get to the science lecture.
After filling up, you only have 15 Â minutes before the lecture starts,
To determine how fast you must drive to be on time to the lecture,
we will determine the average speed you need to travel.
From
Average speed = Distance / Time
Distance = 37.5 miles (Convert to meters)
(NOTE: 1 mile = 1609.344 meters)
Hence, 37.5 miles = 37.5 × 1609.344 miles = 60350.4 meters
∴ Distance = 60350.4 meters
Time = 15 minutes (Convert to seconds)
(NOTE: 1 minute = 60 seconds)
Hence, 15 minutes = 15 × 60 seconds = 900 seconds
Now, from
Average speed = Distance / Time
Average speed = 60350.4 m / 900 s
Average speed = 67.06 m/s
Hence, you must travel at an average speed of 67.06 m/s to be on time to the lecture.