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Natali [406]
3 years ago
6

A piece of charcoal used for cooking is found at the remains of an ancient campsite. A 1.09 kg sample of carbon from the wood ha

s an activity of 2020 decays per minute. Find the age of the charcoal. Living material has an activity of 15 decays/minute per gram of carbon present and the half-life of 14C is 5730 y. Answer in units of y.
Physics
1 answer:
fgiga [73]3 years ago
5 0

Answer:

t = 17199 years

Explanation:

given,

mass of sample = 1.09 Kg

Activity of living material   = 15 decays / min /g

Activity of living material   = 15 x 1000 decays /min /kg

Activity of living material per 1.09 kg A = 1.09 x 15 x 1000 decays / min

Activity of after time t is A ' = 2020

half life = 57300 years

desegregation constant

λ = 0.693 / 5700

A'= A e^{-\lambda\ t}

A'= 1.09 \times 15 \times 1000 e^{-\lambda\ t}

2020= 1.09 \times 15 \times 1000 e^{-\dfrac{0.693}{5700}\times t}

0.124=e^{-\dfrac{0.693}{5700}\times t}

taking ln both side

\dfrac{0.693}{5700}\times t = 2.09

t = 17199 years

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Generally the torques that will cause the wheel to move with \alpha  =  4.30\ rad/s^2 is mathematically represented as

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       0.0425F_c  -  28.75  =   1.1125  *4.30    

        F_c  =  789.03 \  N    

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