Two coherent sources, a and b, emit light waves in a medium. the light waves superpose to produce an interference pattern. which of these is true of sources a and b? a) the two broad sources of light were far apart from each other. b) the waves emitted by the two sources have different wavelengths. c) the waves emitted by the two sources have constant phase difference. d) the two sources of light had to be obtained from two different sources.

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.

i would say