John, a fireman, slides down a pole when the fire alarm sounds. He reaches the ground at 5m^-1. Give that his mass is 60kg. Find the friction that acts against his motion as he slides down the pole.

Sorry sis don't know the meaning of the following

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.

there are no contact forces mentioned on the list of choices that you've provided.