Answer:
B
Step-by-step explanation:
So we have the formula:
And we want to solve it for r.
So, let's first divide both sides by π and h. This will cancel out the right side:
Now, take the square root of both sides:
And we're done!
Our answer is B.
I hope this helps!
Answer:
The time the trip takes Kelly is approximately 34 minutes
Step-by-step explanation:
The topic examined by the question is the relationship between speed, distance traveled, and time which is presented here as follows;
The given parameters of the journey are;
The time it takes Mike to travel from point 'a' to point 'b' = 45 minutes
The speed with which Mike travels = 60 miles an hour
The speed with which Kelly travels the same trip = 80 miles an hour
Let 'd' represent the distance from point 'a' to point 'b', and let 't' represent the time the trip takes Kelly
For Mike, we have;
S = d/t
∴ d = S × t
Where;
S = 60 miles per hour
t = 45 minutes = 0.75 hour
d = 60 miles/hour × 0.75 hour = 45 miles
The distance from point 'a' to point 'b' = d = 45 miles
Similarly, from S = d/t, we have for Kelly the time 't' given as follows;
t = d/S
Where;
S = 80 miles/hour
d = 45 miles
∴ t = 45 miles/(80 miles/hour) = 9/16 hour = 9/16 hour × 60 min/hour = 33.75 minutes
The time the trip takes Kelly = 33.75 minutes ≈ 34 minutes.