# 25 Two cars that may collide at 12:30 PM

**Problem 25**

One city E, is 20 miles north and 20 miles east of another city, F. At noon a car starts south from E at 40 mi/hr, at 12:10 PM, another car starts east from F at 60 mi/hr. Find the rate at which the cars approach each other between 12:10 PM and 12:30 PM. What happens at 12:30 PM?

**Solution 25**

Velocity of approach,

$v = \sqrt{60^2 + 40^2}$

$v = \sqrt{60^2 + 40^2}$

$v = 72.11 \, \text{ mi/hr}$ *answer*

At 12:30 PM

Distance traveled by car from E

= 40(30/60)

= 20 miles

Distance traveled by car from F

= 60 [(30 - 10)/60]

= 20 miles

The cars may/will collide at this time. *answer*