You use an inclined plane to move furniture into a truck. You perform 224 kJ of work, but only do 91 kJ of useful
work. What is the efficiency of the inclined plane?
A. 12.8%
B. 40.6%
C. 68.2%
D. 246.1%

what was the answer?

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.

this is poiselle's equation from fluid mechanic in physics. mech eng

we need to know the time interval during which the force acts. impulse of force = momentum change