Answer
He got an 80
Step-by-step explanation:
50 - 10 = 40
40/50 as a whole number is 80
Answer:
Step-by-step explanation:
Slopes can be negative, zero, positive or undefined.
A slope that is less than zero is a negative slope, which you see dropping (moving downward) as you move to the right.
Answer:
23 years
Step-by-step explanation:
Step 1: Calculate the rate constant (k) for the radioactive decay
A radioactive substance with initial concentration [A]₀ decays to 97% of its initial amount, that is, [A] = 0.97 [A]₀, after t = 1 year. Considering first-order kinetics, we can calculate the rate constant using the following expression.
ln [A]/[A]₀ = - k.t
k = ln [A]/[A]₀ / -t
k = ln 0.97 [A]₀/[A]₀ / -1 year
k = 0.03 year⁻¹
Step 2: Calculate the half-life of the substance
We will use the following expression.
= ln2/ k = ln 2 / 0.03 year⁻¹ = 23 years
Is there a picture that I can see so I can hopefully help you out?
Answer:
0.75m
Step-by-step explanation:
The volume of a prism is:
the area of the cross section × length
In this case the cross section is the circle so the formula is
v = πr²h
volume = 21m³
height or length = 12m
Sub in the values:
21 = πr² × 12
1.75 = πr² (I divided both sides by 12)
0.5570423008 = r² (I divided both sides by π)
r = 0.74635... (I square rooted both sides)
r ≈ 0.75m (to 2 d.p)
