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
4/6
As there are 4 numbers on the dice and there are 6 numbers all together on a dice.
Hope this helps
30.6 because 10.2 times 30 is 30.6
Answer:
The number of trees at the begging of the 4-year period was 2560.
Step-by-step explanation:
Let’s say that x is number of trees at the begging of the first year, we know that for four years the number of trees were incised by 1/4 of the number of trees of the preceding year, so at the end of the first year the number of trees was
, and for the next three years we have that
Start End
Second year 
-------------- 
Third year 
-------------
Fourth year 
--------------
So the formula to calculate the number of trees in the fourth year is
we know that all of the trees thrived and there were 6250 at the end of 4 year period, then
⇒
Therefore the number of trees at the begging of the 4-year period was 2560.
Answer:
Step-by-step explanation:
a1 = 51 + (1 -1 ) * 0.8
a1 = 51
a2 = 51 + (2 - 1)*0.8
a2 = 51 + 0.8
a2 = 51.8
a3 = 51 + (3 - 1)*0.8
a3 = 51 + 2*0.8
a3 = 51 + 1.6
a3 = 52.6
a4 = 51 + (4 - 1)*0.8
a4 = 51 + 2.4
a4 = 53.4
