A North-South highway intersects an East-West highway at a point .
An automobile crosses at 10:00 AM, traveling east at a constant rate of 20 mph.
At that same instant another automobile is two miles north of , traveling south at 50 mph.
(a) Find a formula which expresses the distance between the automobiles
. . .at time (hours) after 10:00 AM.
(b) At what time will the automobiles be 104 miles apart?
I don't agree with either of their answers . . .Code:Q * | 50t | | B * | * d 2-50t | * | * - - P * - - - - - * - - | 20t A |
At 10 AM, the first car is at point .
. . hours later, it is at point
At 10 AM, the second car is at point .
. . hours later, it is at point .
. . Hence: .
Pythagorus says: .
(a) Then we have: .
Square both sides: .
Divide by 4: .
Quadratic Formula: .
And the positive root is: .