6 kg block slides to the east across a frictionless surface with a momentum of 30 kg x meters per second strikes an object with an impulse of 10 newtons per second to the west of the block, what is the speed of the block at collission

Explanation:

Initial momentum = 30 kg m/s .

impulse on the object = 10 N s towards west . = - 10 Ns

impulse = change in momentum

Let velocity after impulse be v

momentum after impulse = 6 v

change in momentum = 6v - 30

So

- 10 = 6v - 30

20 = 6v

v = 3.33 m /s

Since the velocity is positive , that means it is moving in the same direction as earlier .

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.