The time it takes for 1g of strontium-90 to decay to 250 mg is; 57.6 years
<h3>What is the half life of an element?</h3>
The formula for half life is;
A(t) = A₀ * (¹/₂)^(t/t_1/2)
Where;
A(t) is amount left after t years
A₀ the initial quantity of the substance that will undergo decay;
t_1/2 is the half-life of the decaying quantity.
We are given;
t_1/2 = 28.8 years
A₀ = 1 g
A(t) = 250 mg = 0.25 g
Thus;
0.25 = 1 * (¹/₂)^(t/28.8)
log 0.25 = (t/28.8) log (1/2)
-0.60206 = (t/28.8) * -0.3010
t = 2 * 28.8
t = 57.6 years
Read more about half life at; brainly.com/question/11152793
The supply curve will be composed of the following points
(10, 1000) from the statement: 1000 shoes in the market at $10
(25, 1200) from the statement: 12000 shoes at $25 per pair
(40, 1400) from the statement: <span>$40 per pair, the existing firms increase production to 1400 each</span>
Answer:
0.027 cubic ft/min
Explanation:
Volume of water is V=V(t) Depth of water is h=h(t)
The relationship between V and h is
V=π/3.r2.h
Let
h0= the height of the cylinder = 24ft, r0= the radius of the opening = 10ft.
Since water level (h) rise with respect to flow rate we find an expression for r and substitute into V
r/h = r0/h0= 10/24 = 5/12
r = (5/12) h,
Substitute for r in V
so,
V=1/3.π.(h2)square = 1/3.π. 25/144.(h3)
When
h= 16ft
and dV/dt = 20ft3/min
,
dV/dt =1/3*π*25/144*h3*(dh/dt)
20ft3/min= 1/3*π* 25/144*h3*(dh/dt)
20 = 1/3*π*(16)3.(dh/dt)
Make dh/DT subject of formula
dh/dt=(20*3*144)/(25*π*4096) = 8640/321740.8
=
dh/dt= 0.027 ft3/min
The answer is D. Assessment is appropriate for infants and toddlers. It's actually recommended. Screenings of the children is not going to document their growth. There is technically a reliable way. And recording developmental milestones like their first word and when they start walking, crawling and running is extremely crucial in a child's learning process.
