Final answer:
The bicyclist spent approximately 2.52 hours on the entire trip when traveling the first 30 km at 18 km/hr, and the remaining 17 km at 20 km/hr.
Step-by-step explanation:
To determine the total time t that the bicyclist spent on the entire trip when the speed v is 18 km/hr, we need to calculate the time taken for each segment of the journey and then sum them up. We are given:
- For the first 30 km, the speed is v km/hr.
- For the remaining 17 km, the speed is v + 2 km/hr (2 km/hr faster than the original speed).
Let's calculate the time for each segment of the trip:
- Time for the first 30 km: t1 = distance / speed = 30 km / v
- Time for the remaining 17 km: t2 = distance / speed = 17 km / (v + 2)
Now we plug in the value of v = 18 km/hr:
- First segment: t1 = 30 km / 18 km/hr = 1.6667 hours
- Second segment: t2 = 17 km / 20 km/hr = 0.85 hours
Total time spent on the trip: t = t1 + t2 = 1.6667 hours + 0.85 hours = 2.5167 hours, or approximately 2.52 hours.