Erica is hiking down a mountain. She descends at a rate of 36 feet per hour. She began the descent at 10 a. M. And finished at 6 p. M. What was her change in elevation after two hours?

72 feet

Step-by-step explanation:

Given that:

The speed of Erica while descending down the mountain = 36 feet per hour

Time at which the descent was started = 10 AM

Time at which the descent was finished = 6 PM

To find:

The change in elevation after two hours ?

Solution:

First of all, let us learn about the relation between speed, distance and time.

The formula between speed, distance and time is given as:

Here, we are given that:

Speed = 36 feet per hour

Time = 2 hours

We have to find the Distance now.

Putting the given values:

Change in elevation = 72 feet

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)

answer: a

step-by-step explanation:

if xy ~ yz therefore xy would be the same length as yz