Which best explains what happens to the motion of the pendulum? a. the mechanical energy transforms to thermal energy as the pendulum slows and eventually stops moving. b. the mechanical energy disappears as the pendulum slows and eventually stops moving. c. the pendulum will continue moving at the same speed until someone stops it because energy cannot be destroyed. d. the pendulum will slow down but will never stop moving because energy cannot be destroyed.

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.