If a radioactive isotope that was injected into your bloodstream has a half-life of 5 hours, how many hours do you have to wait before the amount of this isotope in your body is 1/16 its original amount?

Total time = 20 hours

Explanation:

Half life is the amount of time it takes for a substance to decay tohalf of it's original amount.

Half life = 5 hours.

We have to obtain the number of half lives to get the time required.

1st half life = 1/2

2nd half life = 1/4

3rd half life = 1/8

4th half life = 1/16

So ffour half lives.

Total time = number of half lives * Time of half life

Total time = 4 * 5

Total time = 20 hours

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be