Process of science: explaining apparent retrograde motion part a at most times, mars appears to move relative to the stars. the exceptions are during its periods of apparent retrograde motion, when mars appears to move relative to the stars. check two responses below, one for each of the two blanks in the question. blank 1) to the right (westward) (blank 1) to the left (eastward) (blank 1) fast (blank 1) slow (blank 2) to the right (westward) (blank 2) to the left (eastward) (blank 2) fast (blank 2) slow

the displacement produced by the body.  

the amount of force subjected to the body.  

the angle between the direction of force and displacement

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.