Get detailed and reliable answers to your questions on IDNLearn.com. Get timely and accurate answers to your questions from our dedicated community of experts who are here to help you.
Answer:
The rate at which the distance between the cars increasing two hours later=52mi/h
Step-by-step explanation:
Let
Speed of one car, x'=48 mi/h
Speed of other car, y'=20 mi/h
We have to find the rate at which the distance between the cars increasing two hours later.
After 2 hours,
Distance traveled by one car
[tex]x=48\times 2=96 mi[/tex]
Using the formula
[tex]Distance=Time\times speed[/tex]
Distance traveled by other car
[tex]y=20\times 2=40 mi[/tex]
Let z be the distance between two cars after 2 hours later
[tex]z=\sqrt{x^2+y^2}[/tex]
Substitute the values
[tex]z=\sqrt{(96)^2+(40)^2}[/tex]
z=104 mi
Now,
[tex]z^2=x^2+y^2[/tex]
Differentiate w.r.t t
[tex]2z\frac{dz}{dt}=2x\frac{dx}{dt}+2y\frac{dy}{dt}[/tex]
[tex]z\frac{dz}{dt}=x\frac{dx}{dt}+y\frac{dy}{dt}[/tex]
Substitute the values
[tex]104\frac{dz}{dt}=96\times 48+40\times 20[/tex]
[tex]\frac{dz}{dt}=\frac{96\times 48+40\times 20}{104}[/tex]
[tex]\frac{dz}{dt}=52mi/h[/tex]
Hence, the rate at which the distance between the cars increasing two hours later=52mi/h