The half-life of Cobalt 60 is 5.27 years. This means that after this time, only 50 % of the initial amount of Cobalt is left. The relationship between the number of nuclei left at time t and the time, for a radioactive decay, is given by
where
is the number of nuclei left at time t,
is the number of nuclei at t=0, and
is the half-life. For cobalt,
.
We can re-arrange the formula as
and then
the problem asks for the time t at which only 20% of cobalt is left, that means the time t at which
therefore, using this into the previous equation, we get
so, after a time of 12.24 years, only 20% of cobalt is left.
The formula of Gay-Lussac's law is Pi/Ti = Pf/T<span>f</span>
Answer:
The plane will be located directly above the bomb because they both have the same horizontal speed.
This heats up when an electric current passes through it, and produces light as a result. The resistance of a lamp increases as the temperature of its filament increases. The current flowing through a filament lamp is not directly proportional to the voltage across it.
The particle will have an energy of 12U0. A particle travels at an initial velocity from point B to point A, gaining U0 joules of kinetic energy along the way. The constant force at this point is equal to 12F.
<h3>Does 9.8 represent gravity?</h3>
The acceleration which gravity gives to objects falling freely serves as a gauge of its strength. The gravity's acceleration at Earth's surface is approximately 9.8 meters (32 feet) per second every second.
<h3>What is a good illustration of gravity?</h3>
The following are a few instances of the power of gravity: the energy holding the gases inside the sun. the power behind a ball's descent after being thrown into the air. the force that makes an automobile coast down even when the gas is not depressed.
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