Where is the sun rays strike earth most directly and least directly

The sun rays strike earth most directly at the equator and that's due to the Earth angle of rotation, that makes it possible for the sun to hit most directly at the equate.

The sun rays strike earth least directly at the poles and that's also due to the Earth angle of rotation., that's why the poles are colder than the equator.

truck y has a greater velocity than truck x.

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.