I am not answering all the questions.
I will only do the first one.
A = pir^2
A = pi(6)^2
A = 36pi
You do the rest.
Answer: 24
Step-by-step explanation: you add 9+9+3+3 and you get 24
Answer:
at 8 pm the temperature will be -9 degrees. and at midnight the temperature will be negitive twenty one(-21) degrees
Step-by-step explanation:
the start time is 12 pm and finish is 12 am and every hour your going to subtract 3 from the given degree so 15-3= 12 , 12-3=9 ect.
Answer:
A) 277 million years
Step-by-step explanation:
Here, decay of U-238 is first order reaction. (since most of the nuclear decays are first order).
so, the equation t =
× ln(
)
where, t = time from start of reaction
k = reaction constant
A(0) = initial concentration; A = present concentration.
⇒ 4.5 billion = 4500 million years =
× ln2.
Now, given 95.82% of parent U-238 isotope is left.
⇒ t =
× ln(
)
t =
× ln(
)
⇒ t ≅ 277 million years.