Question

1. 1. A police cruiser approaching a right-angled intersection from the north, is chasing a speeding car that has turned the corner and is now moving due east. When the cruiser is 0:6 miles north of the intersection and the car is 0:8 miles to the east, the police determine with radar that the distance between them and the car is increasing at a rate of 20 mph. If the cruiser is moving at 60 mph at the instant of the measurement, how fast is the car moving?

For this question, I know how to solve it because of a brief answer key, but I do not get how the value of s, or the distance between the cruiser and the car is 1. I get how x, the distance of the car, is 0.8 and how y, the distance of the cruiser is 0.6. But why is s=1?

2. A man starts walking north at a speed of 1.5 m/s and a woman starts at the same point P at the same time walking west at a speed of 2m/s. At what rate is the distance between the man and the woman increasing one minute later?

I have no idea how to do this question, and am getting confused by the concept in general. Would someone mind explaining to me how to approach this question?
I have drawn a diagram, which is a right triangle, but I have no idea how to figure out the lengths from only being given the speeds.

Thanks in advance!

Answer 1

I answered the first question back in 2012

http://www.jiskha.com/display.cgi?id=1326819217

See if you can follow the same way for the 2nd question.
The second question is actually easier
Be sure to use 60 seconds for 1 minute at the end