Final answer:
It will take Ken approximately 23.48 minutes to glide down from the 648.6 ft cliff.
Step-by-step explanation:
To calculate how long it will take Ken to glide down from a 648.6 ft cliff, we can use the equation: Time = Distance / Rate.
Given that Ken reduces his altitude by 27.6 ft every minute, we need to find how many minutes it will take to cover the distance of 648.6 ft. So, Time = 648.6 ft / 27.6 ft/min.
Dividing 648.6 ft by 27.6 ft/min, we find that it will take Ken approximately 23.48 minutes to glide down from the cliff.