Question

On your wedding day you leave for the church 30 minutes before the ceremony is scheduled to start. The church is only 10 miles away, but you have to make an unanticipated stop for construction work on the road. As a result, your average speed for the first 15 minutes is only 5 miles per hour. What average speed do you need to go for the rest of the trip to get to the church on time

Answer 1

You need to have an average speed of at least 35 miles per hour for the rest of the trip to get to the church on time

Explanation:

We use the following relation to solve the question:

`v = (d)/(t)`

In which v is the velocity, d is the distance, and t is the time.

First 15 minutes:

Time of 15 minutes = 0.25 hour, so
`t = 0.25`

Velocity of 5 miles per hour. So the distance is of:

`d = vt = 5*0.25 = 1.25`

Final 15 minutes:

The will need to drive 10 - 1.25 = 8.75 miles in 15 minutes = 0.25 hours. So, the average speed will need to be of at least:

`v = (d)/(t) = (8.75)/(0.25) = 35`

You need to have an average speed of at least 35 miles per hour for the rest of the trip to get to the church on time