The fourth dimension is technically time. the fourth dimension that you are talking about is actually impossible to comprehend.
To respond to the question, we need the data provided with the question.
The total distance is 70km.
The total time is 60 minutes or 1 hour.
Speed=Distance÷Time
=70÷1
=70km/h
Answer:
52.47706 mph
54.5 mph
Explanation:
The average speed is given by


Julie's average speed on the way to Grandmother's house is 52.47706 mph

Average speed on the return trip is 54.5 mph