If a man has a mass of 74 kilograms runs 800 meters in 150 seconds, what is
his average momentum?

3.94 kg*m/s

Explanation:

Use eqation for momentum: p=m*V

m-mass

V-speed

Speed is calculated using: V=S/t

S-distance (800m)

t-time(150 s)

V=S/t

V=800m/150s

V=5.33m/s

Now calculate momentum:

p=m*V

p=74kg*5.33m/s

p=3.94kg*m/s

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.