A model roller coaster car weighing 300 Kg is accelerated with a constant force F between points A and B over a period of 1.5 seconds. When the car gets to point C, the normal force exerted by the track on the car is in the downward direction and equal in magnitude to the weight of the car. (i) Determine the magnitude of F. (ii) determine the maximum height reached by the car on the upward slope. The radius of curvature of the loop is 10 m. Neglect friction losses.

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.