Answer : The time passed in years is 20.7 years.
Explanation :
Half-life = 28.1 years
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = time passed by the sample = ?
a = initial amount of the reactant = 1.00 g
a - x = amount left after decay process = 0.600 g
Now put all the given values in above equation, we get
Therefore, the time passed in years is 20.7 years.
Answer:
The first law states that if the net force is zero, then the velocity of the object is constant.
I<span>n </span>direct current<span> (</span>DC), the electric charge (current<span>) only flows in one direction. Electric charge in </span>alternating current<span> (</span>AC<span>), on the other hand, changes direction periodically. The voltage in </span>AC<span> circuits also periodically reverses because the </span>current<span> changes direction.</span>
That's one of the three changes that are called "acceleration".
The other two are:
-- increase in the magnitude
-- change in direction.
Some might call a decrease in the magnitude "deceleration".
