Answer:
304(pi) g
Step-by-step explanation:
First we find the volume of the hollow ball. Then we find the mass using the volume and density.
Let R = exterior radius = 3 cm
Let r = interior radius = 2 cm
volume = exterior volume - interior volume
volume = (4/3)(pi)R^3 - (4/3)(pi)r^3
volume = (4/3)(pi)(R^3 - r^3)
volume = (4/3)(pi)(3^3 - 2^3) cm^3
volume = (4/3)(pi)(27 - 8) cm^3
volume = (76/3)pi cm^3
Now we use the density and the volume to find the mass.
density = mass/volume
mass = density * volume
mass = 12 g/cm^3 * (76/3)pi cm^3
mass = 304(pi) g
Answer: 304(pi) g
Step-by-step explanation:
The amount of time from 10pm to 7am is 9 hours. However, the time indicated is 7:10am. Since there are 60 minutes in an hour, 10 min is equal to 1/6 of an hour. Therefore, the total time that the water level of the pool decreased is 
hours or 
hours. To find the rate at which the water level decreased, we divide the change in the water (in inches) by the time it took to reach that level. So we write
rate of change 
If you have given an equation, you see the x and y in it. Just taking second equation and think any common factor between x's variable. With common factor, multiply both and you will find the value of y and put it in any equation, you will find the value of X
-2(4y+6) = 52
-8y -12 = 52
Add 12 on both sides
-8y= 64
Y= -8
Hope this helps!
