Answer:
324π in²
Step-by-step explanation:
The surface area of a sphere = 4πr² ( r is the radius )
Calculate r using the volume (V) formula
V = πr³
Here V = 972π , thus
πr³ = 972π ( divide both sides by π )
r³ = 972 ( multiply both sides by 3 to clear the fraction )
4r³ = 2916 ( divide both sides by 4 )
r³ = 729 ( take the cube root of both sides )
r = = 9
Thus
surface area = 4π × 9² = 4π × 81 = 324π in²
Step-by-step explanation:
We want to find two things-- the speed of the boat in still water and the speed of the current. Each of these things will be represented by a different variable:
B = speed of the boat in still water
C = speed of the current
Since we have two variables, we will need to find a system of two equations to solve.
How do we find the two equations we need?
Rate problems are based on the relationship Distance = (Rate)(Time).
Fill in the chart with your data (chart attached)
The resulting speed of the boat (traveling upstream) is B-C miles per hour. On the other hand, if the boat is traveling downstream, the current will be pushing the boat faster, and the boat's speed will increase by C miles per hour. The resulting speed of the boat (traveling downstream) is B+C miles per hour. Put this info in the second column in the chart. Now plug it into a formula! <u>Distance=(Rate)(Time) </u>Now solve using the systems of equations!
