Question

Erik's disabled sailboat is floating at a stationary location 3 miles east and 3 miles north of Kingston. A ferry leaves Kingston heading due east toward Edmonds at 15 mph. At the same time, Erik leaves the sailboat in a dinghy heading due south at 10 ft/sec (hoping to intercept the ferry). Edmonds is 6 miles due east of Kingston.

Required:
Compute Erik's speed in mph and the ferry's speed in ft/sec.

Answer 1

(a)6.82mph

(b)22 ft/sec

Explanation:

Eric's Speed = 10 ft/sec

The Ferry's Speed = 15 miles per hour

Conversion Unit

• 1 mile = 5280 feet
• 1 hour = 3600 seconds

Guide

• When converting from a smaller unit to a larger unit we divide
• When converting from a larger unit to a smaller unit we multiply

(a)To convert Eric's Speed 10 ft/sec to miles per hour

`(10 \:ft)/(seconds) =(10 / 5280 \:miles)/(1 / 3600\: hour) \\=6.82 miles \:per\: hour`

(b)To convert the Ferry's Speed 15 mph to ft/sec

`(15 \:miles)/(hour) =(15 X 5280 \:foot)/(1 X 3600\:seconds) \\=22 foot \:per\: seconds`