The mass of substance left after 7 days is 13.09 g
The mass of substance left, N is given by
N = N₀exp(-λt) where λ = decay constant and N₀ = initial mass of substance present = 24 g and t = time
Also, λ = 0.693/t' where t' = half-life of iodine = 8 days
So, λ = 0.693/t'
λ = 0.693/8
λ = 0.086625/day
Since the mass of substance left is N = N₀exp(-λt) and we require the mass of substance after t = 7 days,
N = N₀exp(-λt)
N = 24 gexp(-0.086625/day × 7 days)
N = 24 gexp(-0.606375)
N = 24 g × 0.5453
N = 13.09 g
So, the mass of substance left after 7 days is 13.09 g
Learn more about radioactive decay here:
brainly.com/question/23705307
Answer: sin(x) / cos(x)
Step-by-step explanation: This is just a trigonometric identity you should have memorized :)
The degree measure of one and a half full turns is 540 degrees
Answer:
y = 1/e
y = 0.37
Step-by-step explanation:
y = (ln x)/x; (e, 1/e)
Step 1
Find the point of tangency.
It's given as (e,1/e) or (2.72,0.37)
Step 2
Find the first derivative, and evaluate it at x=e
Using product rule.
d(uv) = udv + vdu
Where u = lnx and v = 1/x
du = 1/x , dv = -1/x^2
f'(x) = -lnx/x^2 +1/x^2
f'(x) = (1-lnx)/x^2
At x = e
f'(e) = (1-lne)/e^2
f'(e) = 0
The slope of the tangent line at this point is m= 0
Step 3
Find the equation of the tangent line at (e,1/e) with a slope of m=0
y−y1 = m(x - x1)
y-(1/e) = 0(x-1)
y = 1/e
y = 0.37
