Q:

Ubehebe Crater in Death Valley has a diameter of a little morethan 1−2 mile. If Latisha walks around its rim at a rate of 2 miles per hour,about how long will it take her to walk all the way around the crater?Find your answer to the nearest tenth. Use 3.14 for π.

Accepted Solution

A:
First, we are going to use the formula of the circumference of a circle: [tex]C=2 \pi r[/tex]
where 
[tex]C[/tex] is the circumference of the circle.
[tex]r[/tex] is the radius of the circle.

We know for our problem that the diameter of Ubehebe Crater is 1 mile. Since the radius of a circle is half its diameter, the radius of our crater will be: [tex]r= \frac{1}{2} =0.5[/tex]. Lets replace that value in our formula:
[tex]C=2 \pi r[/tex]
[tex]C=2*3.14*0.5[/tex]
[tex]C=3.14[/tex] miles

Next, we are going to use the distance speed time formula: [tex]t= \frac{d}{s} [/tex]
where
[tex]t[/tex] is time
[tex]d[/tex] is distance
[tex]s[/tex] is speed

We know for our problem that Latisha walks around its rim at a rate of 2 miles per hour, so her speed is 2 mph; therefore, [tex]s=2[/tex]. We also know for our previous calculation that the circumference of the crater is 3.14 miles, so [tex]d=3.14[/tex]. Lets replace those values in our formula to find [tex]t[/tex]:
[tex]t= \frac{d}{s} [/tex]
[tex]t= \frac{3.14}{2} [/tex]
[tex]t=1.6[/tex] hours

We can conclude that it will take Latisha 1.6 hours to walk all the way around the crater.