We can’t click on the link maybe take a pic
Deena drove:
585 miles/9 hrs
....which means
her average rate was:
65miles/hour
whereas
Kristen drove:
605 miles/11 hrs
....meaning
her average rate was:
55 miles/hour
Therefore, Deena drove at a faster rate than Kristen
Answer:
18.87 km/hr
Step-by-step explanation:
First boat is heading North with a speed of 10 km/hr.
Second boat is heading West with a speed of 16 km/hr.
Time for which they move = 2.5 hours
To find:
The speed at which the distance is increasing between the two boats.
Solution:
Let the situation be represented by the attached diagram.
Their initial position is represented by point O from where they move towards point A and point B respectively.
![Distance = Speed \times Time](https://tex.z-dn.net/?f=Distance%20%3D%20Speed%20%5Ctimes%20Time)
![Distance\ OA = 10 \times 2.5 = 25\ km](https://tex.z-dn.net/?f=Distance%5C%20OA%20%3D%2010%20%5Ctimes%202.5%20%3D%2025%5C%20km)
![Distance\ OB = 16 \times 2.5 = 40\ km](https://tex.z-dn.net/?f=Distance%5C%20OB%20%3D%2016%20%5Ctimes%202.5%20%3D%2040%5C%20km)
We can use Pythagorean Theorem to find the distance AB.
AB is the hypotenuse of the right angled
.
According to Pythagorean theorem:
![\text{Hypotenuse}^{2} = \text{Base}^{2} + \text{Perpendicular}^{2}\\\Rightarrow AB^{2} = OA^{2} + OB^{2}\\\Rightarrow AB^2 = 25^2 + 40^2\\\Rightarrow AB^2 = 2225^2\\\Rightarrow AB^2 \approx 47.17\ km](https://tex.z-dn.net/?f=%5Ctext%7BHypotenuse%7D%5E%7B2%7D%20%3D%20%5Ctext%7BBase%7D%5E%7B2%7D%20%2B%20%5Ctext%7BPerpendicular%7D%5E%7B2%7D%5C%5C%5CRightarrow%20AB%5E%7B2%7D%20%3D%20OA%5E%7B2%7D%20%2B%20OB%5E%7B2%7D%5C%5C%5CRightarrow%20AB%5E2%20%3D%2025%5E2%20%2B%2040%5E2%5C%5C%5CRightarrow%20AB%5E2%20%3D%202225%5E2%5C%5C%5CRightarrow%20AB%5E2%20%5Capprox%2047.17%5C%20km)
The speed at which distance is increasing between the two boats is given as:
![\dfrac{47.17}{2.5} \approx 18.87\ km/hr](https://tex.z-dn.net/?f=%5Cdfrac%7B47.17%7D%7B2.5%7D%20%5Capprox%2018.87%5C%20km%2Fhr)
First one is -6 and the second one is -3