Carbon-14 is naturally created with the interaction of high-energy cosmic rays with atmospheric nitrogen. As part of the atmosphere, living organisms take in the carbon and incorporate this into living tissues. As long as the organism is alive and breathing, it keeps adding new carbon-14. When the organism dies, it stops gaining carbon-14 - or anything else, of course.
Carbon-14 is slightly radioactive, with a half-life of about 5700 years. If we assume that the atmospheric production of carbon-14 has been steady for the last 100,000 years, we can calculate the approximate age of when the organism died by determining what percentage of carbon-14 still exists in the dead material.
Paleo-archaeologists and anthropologists use this information when studying old cultures and civilizations.
Answer:
-5 cm
Explanation:
We can use the lens equation:
where
f = -7 cm is the focal lenght
p = 14 cm is the distance of the object from the lens
q is the distance of the image from the lens
Solving the equation for q, we find
Answer:
We will use Potential Energy Formula
Potential Energy = mass × gravitation × height
PE = 0,55 × 10 × 4
PE = 22 J (A)
Answer:
α = 2,857 10⁻⁵ ºC⁻¹
Explanation:
The thermal expansion of materials is described by the expression
ΔL = α Lo ΔT
α =
in the case of the bar the expansion is
ΔL = L_f - L₀
ΔL= 1.002 -1
ΔL = 0.002 m
the temperature variation is
ΔT = 100 - 30
ΔT = 70º C
we calculate
α = 0.002 / 1 70
α = 2,857 10⁻⁵ ºC⁻¹
Answer:
The duration of the movie is longer than 2 hrs.
Explanation:
Given:
The duration of the movie observed by the crew on the spacecraft is 2 hrs.
According to time-dilation formula:
Here, is the required time, is the original time, is the velocity of the spacecraft and is the velocity of light.
Since , so .
So the time required will be large.