Answer:
16.7
Step-by-step explanation:
speed is constant at 17 mph
Distance covered after one hour = 17 miles
Distance between port and San Francisco = 3 miles
Speed at which distance changes 1 hour after leaving port :
r² = 17² - 3²
r² = 289 - 9
r = √280
r = 16.733
= 16.7 (nearest tenth )