(GIVE THE ANSWER OR GET REPORTED) Please solve it with the steps​

4. a = 2 m/s² 5. m = 20 kg

Explanation:

4.

Mass of the book, m = 2kg

The net force acting on the book, F = 4 N

Let a is the acceleration of the book. We know that,

F = ma

Put all the values,

So, the acceleration of the book is equal to .

5.

Kinetic energy of the car, K = 4000 J

Speed of the car, v = 20 m/s

We need to find the mass of the car. The formula for the kinetic enregy is given by :

So, the mass of the car is equal to 20 kg.

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.