a car starts from rest and travels for 5.0 s with a uniform acceleration of -1.5 m/s^2.the driver then applies brakes, causing a uniform acceleration of -2.1m/s^2 for an interval of 3.0s

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.

answer///terminator or twilight zone;

3. dark matter

empty space could also be a simple vacuum