SOLUTION: Alice leaves her house, driving East at 45 miles per hour.30 minutes later, her husband Dave notices she forgot her cell phone and sets off after her. How fast must Dave travel in

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Alice leaves her house, driving East at 45 miles per hour.30 minutes later, her husband Dave notices she forgot her cell phone and sets off after her. How fast must Dave travel in       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 877072: Alice leaves her house, driving East at 45 miles per hour.30 minutes later, her husband Dave notices she forgot her cell phone and sets off after her. How fast must Dave travel in order to catch up with Alice 3 hours after he leaves?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Alice leaves her house, driving East at 45 miles per hour.
30 minutes later, her husband Dave notices she forgot her cell phone and sets off after her.
How fast must Dave travel in order to catch up with Alice 3 hours after he leaves?
:
From the information given we know:
3.5 hrs is A's travel time
and
3 hrs is Dave's travel time
:
let s = speed required for D to catch A
:
When D catches A, they will have traveled the same distance
Write a dist equation; dist = speed * time
3s = 3.5(45)
3s = 157.5
s = 157.5/3
s = 52.5 mph to catch A in 3 hrs
;
:
Check this by finding the distance each traveled
3 * 52.5 = 157.5
3.5 * 45 = 157.5 mi