On an inclined plane with angle α to the horizontal it leans a rod which, due to a guide, it can move only vertically. find the velocity "u" with which will climb the rod when the inclined plane is moved to the left with the constant velocity "v".
v, alpha

u=?
me with explanations and a draw i don't get it when in decomposition of "u" what vector it will have the value = value of v and i don't know how to recognize the alpha angle in the decomposition.

u = - tan * v

Explanation:

Here is a different perspective. An observer that moves along the incline has a velocity w. The velocity v of the incline is equal to the horizontal componant of the observer with the opposit sign. The velocity u of the rod is the vertical component of the observer.

You get the following equations:

u = w sin

v = - w cos

Dividing both equations give:

u/v = -tan

u = - tan * v

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.