If you have a 200g sample of a radioactive isotope that has a half life of 50 years, hc
1 answer:
Answer:
The correct option is;
a. 12.5 g
Explanation:
The given parameters are;
The initial mass of the radioactive substance = 200 g
The half life of the radioactive substance = 50 years
The time duration for the disintegration = 200 years
The formula for half life is given as follows;
Where:
N(t) = Quantity of the remaining substance
N₀ = Initial radioactive substance quantity = 200 g
t = Time duration = 200 years
= Half life of the radioactive substance 50 years
Therefore, we have;
Therefore, at the end of 200 years, the quantity left = 12.5 g.
You might be interested in
Answer:
(a) The absolute pressure at the bottom of the freshwater lake is 395.3 kPa
(b) The force exerted by the water on the window is 36101.5 N
Explanation:
(a)
The absolute pressure is given by the formula
Where is the absolute pressure
is the atmospheric pressure
is the density
is the acceleration due to gravity (Take
)
h is the height
From the question
h = 30.0 m
= 1.00 × 10³ kg/m³ = 1000 kg/m³
= 101.3 kPa = 101300 Pa
Using the formula
P = 101300 + (1000×9.8×30.0)
P = 101300 + 294000
P =395300 Pa
P = 395.3 kPa
Hence, the absolute pressure at the bottom of the freshwater lake is 395.3 kPa
(b)
For the force exerted
From
P = F/A
Where P is the pressure
F is the force
and A is the area
Then, F = P × A
Here, The area will be area of the window of the underwater vehicle.
Diameter of the circular window = 34.1 cm = 0.341 m
From Area = πD²/4
Then, A = π×(0.341)²/4 = 0.0913269 m²
Now,
From F = P × A
F = 395300 × 0.0913269
F = 36101.5 N
Hence, the force exerted by the water on the window is 36101.5 N