A physics student runs along a line tangent to the edge of a motionless merry-go-round and jumps on at the very outside. The merry-go-round has the shape of a uniform disk. A) Make an angular momentum chart to help you keep track of what is and is not changing. Consider the two objects, the student and merry-go-round, with the total angular momentum of these two objects conserved. Must the student have angular momentum before jumping on the merry-go-round?
B) Is linear momentum conserved in this interaction if you just consider the merry-go-round and the student?

We know that angular momentum is mvr

So that of the students initially will be

A1= mvr

and the final of the student and the merrygo round will be

A2= (1/2Mr²+mr)omega

So

Angular velocity (omega)= mvr/(1/2Mr²+mr)

This is the final angular velocity of the system so yea the student must have angular momentum before jumping on the merry-go-round

B. Because of directional changes at every edge of the Merry go round that result in changes in velocity, this results in changes in momentum too thus linear momentum is not conserved

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

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.