Answer:
diameter ≈15.6
Step-by-step explanation:
To solve this;
volume of a sphere = 4/3 πr³
From the question given;
volume of the sphere = 268
lets substitute and solve for r
volume of sphere = 4/3 πr³
268 = 4/3 × 3.14 × r³
268 =4.19 × r³
Divide both-side of the equation by 4.19
268/4.19 = r³
63.96 = r³
Take the cube root of both-side
∛63.96 = r
7.8 ≈ r
but diameter = 2r = 2×7.8 =15.6
The two angles shown are supplementary angles, meaning that there sum equals 180. Knowing this you can set up an equation and solve for h...
3h + 18 + 15h = 180
Combine like terms
18h + 18 = 180
Subtract 18 to both sides
18h + (18 -18) = 180 - 18
18h = 162
Isolate h by dividing 18 to both sides
18h/18 = 162 /18
h = 9
Hope this helped!
Answer:
700 cm
Step-by-step explanation:
1 Meter is 100 Centimeters
The half-life of Po is 139 days, so its decay rate is
0.5 = e^(139k) ==> k = ln(0.5)/139
After some time t, 80% of the material will have decayed and you'll be left with a sample 20% of its original mass:
0.2 = e^(kt) ==> t = ln(0.2)/k = ln(0.2)/ln(0.5) * 139 = 322.748
so your sample is usable for about 323 days.
