The
half-life of this radioactive isotope is 9 months for it decreases to
one-fourth its original amount in 18 months. Half-life means a certain length
of time after which half of the amount of radioactive element has decayed.
Therefore,
the half-life of this particular isotope is 18 months. After 18 months the
isotope was at one-half, then another 18 months, the isotope was at one-fourth,
which is 9 months where one-fourth is one-half of one half.
I don't think you mean 'criteria'. I think you mean three occurrences or
observations that indicate the presence of acceleration.
They are:
-- an object is speeding up
-- an object is slowing down
-- the direction of an object's motion is changing .
Any one of these changes is acceleration.
There's a single term that covers them all. It is "change in velocity".
i added an image. i hope it helped :)
An LED is useful because when a current passes through it, it gives out light.
Answer: please see attached work.
Explanation: please see attached work. Assuming 500 sheets of paper = 20 lb. (typicical value).
