Question

plutonium -240 decays according to the function Q(t)=Qoe^-kt

Answer 1

k = 0.00011
Qo = 36 grams
Q(t) = 12 grams

Find t

Answer 2

\[12 = 36 e ^{-0.00011*t}\]

Answer 3

\[\ln \frac{ 12 }{ 36 } = -.00011*t\]

Answer 4

u have it from there?

Answer 5

A?

Answer 6

oh i didnt calculate,, one sec

Answer 7

9987.38

Answer 8

D

Answer 9

could you help me with one more?

Answer 10

sure

Answer 11

Please, thank you!!

Answer 12

ok we have to test each one

Answer 13

\[P(t) = 64 / [1 + 11e ^{-0.08t}]\]

Answer 14

t = years since 1990
P(t) = Billions of People

Answer 15

In 1990 there were 5.33 billion people? t = 0

5.33 = 64 / [1+11e^-0.08(0)]

Answer 16

recall e^0 = 1

5.33 = 64 / 12 TRUE

Answer 17

B is also True

Answer 18

Because e^-x starts out Huge for small values, then approaches zero as you go off to larger numbers, the denominator will go to 1,
the population will approach 64 billion at large times

Answer 19

could A & C also true?

Answer 20

c is not true, the carrying capacity is 64 billion

Answer 21

A and B are True