Answer:
Quantity remaining= 27.5 grams
Step-by-step explanation:
If the initial quantity of the radioactive isotope= 220 grams
And for each half life it will reduce to half of its original quantity
For first half life
Quantity= 220/2
Quantity= 110 grams
Now for the second half life , the quantity to work with will be 110 grams
Second half life
Quantity= 110/2
Quantity= 55 grams
For the third half life , the quantity to work with is 55 grams
Third half life
Quantity= 55/2
Quantity= 27.5 grams
So after 3 half life's of this radioactive isotope, the amount remaining out of 220 = 27.5 grams.
Another simple way to do this
Since half life reduce the isotope by half of its original.
The third half life will reduce it by (1/2)^3= 1/8
So the quantity remaining= 1/8*220
Quantity remaining= 27.5 grams
Answer:
a = 139.1
b = 56.2
Step-by-step explanation:
A. Reference angle = 68°
Opp = a
Hyp = 150
Therefore:
Sin 68 = opp/hyp
Sin 68 = a/150
150*sin 68 = a
a = 139.1 (nearest tenth)
B. Reference angle = 68°
Adj = b
Hyp = 150
Therefore:
Cos 68 = adj/hyp
Cos 68 = b/150
150*cos 68 = b
b = 56.2 (nearest tenth)
Answer:
1/4 and 3/12
Step-by-step explanation:
Answer:
(7x + 5)m
Step-by-step explanation:
area = base * height = (35x2 + 46x +15) m²
base = (5x + 3)
Using algebraic division, find the height. SEE ATTACHMENT
height = (7x + 5)
