Why is fission not an important energy source in the sun?

Explanation:

Nuclear Fission -

The process of the splitting of atom , by radioactive decay process or by any collisional impact .

Sun contains many radioactive isotopes like , thorium , uranium , etc .

The nuclear fission process is an intrinsic property of the radioactive nuclides.

Nuclear Fusion -

The process , where two or more than two atomic nuclei combines to form one or more different atomic nuclei and subatomic particles .

The energy released in both the process is almost same ,

But on the surface of Sun , hydrogen is abundantly present , hence , hydrogen fusion is possible , so the dominant source of energy on the sun is Fusion .

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.