2) A bully is pushing a boy against a locker as shown with a force of 500N. The angle between his arms and the ground is 40°. Draw a free-body diagram of
the boy and then find the normal force between the boy and the wall.
HELP

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered

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.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.