Seven-eighths of a sample of hydrogen-3 will have become a stable isotope after 36.9 years. what is the half-life of hydrogen-3?

A. 12.3 years

Explanation:

Answer

12.3 years

Step by step Solution

Step 1

The first step is to use the radioactive decay formula to to calculate the radioactive constant for hydrogen 3. The radioactive formula is , where is the amount available at any time,  is the initial amount of substance, is the radioactive decay constant.  We are given the values . We use these values to calculate the constant as follows,

Step 2

The next step is to use the value for the decay constant to calculate  the half life. We notice that at the half life, the value of the material remaining is 0.5. We show the calculation as shown below,

The half life is 12.3 years.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.

answercollision;