a 3.5 kg mass has an initial velocity of 4.0 m/s. How much force is required to increase the velocity of the mass to 8.0 m/s in 3.0 seconds?

4.67 N of force are required

Explanation:

The second Newton's law states the net force exerted on a body of mass m that has an acceleration a, is given by:

F=m.a

On the other hand, the kinematics equations relate the acceleration with the change of speed over time, expressed as:

We are given the initial speed of vo=4 m/s on a mass of m=3.5 Kg, the final speed of vf=8 m/s which took t=3 seconds.

The acceleration is:

Thus, the force is:

4.67 N of force are required

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.