Answer:

Step-by-step explanation:
we are given half-life of PO-210 and the initial mass
we want to figure out the remaining mass <u>after</u><u> </u><u>4</u><u>2</u><u>0</u><u> </u><u>days</u><u> </u>
in order to solve so we can consider the half-life formula given by

where:
- f(t) is the remaining quantity of a substance after time t has elapsed.
- a is the initial quantity of this substance.
- T is the half-life
since it halves every 140 days our T is 140 and t is 420. as the initial mass of the sample is 5 our a is 5
thus substitute:

reduce fraction:

By using calculator we acquire:

hence, the remaining sample after 420 days is 0.625 kg
C kinetic energy. As it loses potential energy, it gain kinetic energy
The answer is 0.0016 or 0.0017
Answer:
126
Step-by-step explanation:
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Answer:
a. 45 π
b. 12 π
c. 16 π
Step-by-step explanation:
a.
If a 3×5 rectangle is revolved about one of its sides of length 5 to create a solid of revolution, we can see a cilinder with:
Radius: 3
Height: 5
Then the volume of the cylinder is:
V=π*r^{2} *h= π*(3)^{2} *(5) = π*(9)*(5)=45 π
b. If a 3-4-5 right triangle is revolved about a leg of length 4 to create a solid of revolution. We can see a cone with:
Radius: 3
Height: 4
Then the volume of the cone is:
V=(1/3)*π*r^{2} *h= (1/3)*π*(3)^{2} *(4) = (1/3)*π*(9)*(4)=12 π
c. We can answer this item using the past (b. item) and solving for the other leg revolution (3):
Then we will have:
Radius: 4
Height: 3
Then the volume of the cone is:
V=(1/3)*π*r^{2} *h= (1/3)*π*(4)^{2} *(3) = (1/3)*π*(16)*(3)=16 π