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Marta_Voda [28]
3 years ago
7

The isotope 239 Pu 94 has a half life of 24,400 years. If a sample of nuclear waste originally contained 12kg of 239 Pu 94, how

much time must pass before the amount falls to 3 kg?
Chemistry
1 answer:
Natasha2012 [34]3 years ago
5 0
Equation for half-lives:

Nt = No x (1/2)^n

No = initial amount
Nt = final amount after t years
n = number of half lives = t/(single half-life)
t = years

Nt = 3/12 = 0.25
No = 12/12 = 1.00
n = t/(24400)

3/12 = (12/12) x (0.5)^(t/24400)
(0.25) = 1.00 x (0.5)^(t/24400)
0.25/1.00 = 0.5^(t/24400)
ln(0.25) = ln(0.5^(t/24400))
ln(0.25) = (t/24400)*ln(0.5)
ln(0.25)/ln(0.5) = (t/24400)
2 = t/24400
2*24400 = t
t = 48800 yrs

answer is <u>t = 48,800 yrs</u>


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3 years ago
Consider the market for paper. Let market demand be given by inverse demand function P d (Q) = 60 − Q, where Q is tons of paper
MakcuM [25]

Answer:

See explaination

Explanation:

Demand for paper is given below:

P(Q)=60-Q,

Number of paper mills=20

The cost curve for firm is given below:

C(Q)=10Q2

The external cost in terms of pollution down river by production of paper is given below:

EC(Q)=10Q2

a. The optimal level of paper production by market can be calcuated by equating MC=P

20Q=P

Q=P/20

b. The optimal level of paper production by market can be calcuated by equating MC=P.

MC=20Q

60-(20Q)=20Q

Q=60/40

Q=1.5

Total quanity by 20 firms will be 1.5*20=30

c. The socially efficient level of paper output is calcuated below:

MC+EC'=20Q+20Q

60-(20Q)=40Q

Q=60/60

Q=1

Total quanity by 20 firms will be 1*20=20

The price will be P=60-20=40

d, The deadweight loss occurs as market price increases and quantity decreases due to the external cost . The deadweight loss is calcuated below:

DWL=(1/2)*change in price* change in quantity

=(1/2)*10*10=50

e. 20 firms merged into one firm to make monopoly firm. The cost function for the monopoly is given below:

Cm(Q)=20*10(Q/20)2

The marginal cost for the monopoly firm will be

MCm=Q

The marginal revenue for the firm is 60-2Q

For optimal output MR is equated to MC

60-2Q=Q

Q=20

P=40.

The monopoly outcome is below the perfect competition outcome and price is higher in comparison to perfect competition. The monopoly outcome is same as socially efficient outcome.

The total surplus for this outcome is sum of consumer surplus and producer surplus and subtraction of external cost

TS=CS+PS-EC

=(1/2)*20*20+(1/2)*40*20-10(20)2

=600-4000=-3400

Due to the external effects the total surplus to the society is negative. In perfect competition this effect is not considered and output produced is high therefore, the external cost will be higher with higher output leading to higher negative social surplus. Generally the monopoly outcome reduces the total social surplus but in case of externality, the monopoly total surplus is higher than the perfect competition.

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Explanation:

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When a gas is cooled at constant pressure, what happens to its molecules and volume?
Dima020 [189]
Assuming it's a perfect gas, we have PV=nRT hence if T goes down, V goes down up. The volume will decrease.
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Answer:

850

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It's between 840 and 860

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