Technician A says that the pressure differential switch may need to be re-centered after bleeding the brakes. Technician B says that there are several types of pressure differential switches, and each requires a different method of re-centering. Who is correct?
a. Technician A
b. Technician B
c. Both Technician A and Technician B
d. Neither Technician A nor Technician B

Option C

Both Technician A and Technician B is correct

The pressure differential valve is the equipment that warns you if you leak one of your brake circuits. After draining and refilling some brake system pressure differential switch may be actuated and an indication light may be illuminated. If the indication light sojourns sparked after draining the valve piston may demand to be re-centered. If the pressure is replaced to the brake line and your brakes appear to be running accurately over, then the reset button operated.

The common practical method to re-center the piston is to fix the failure, drain the system and then generate a pressure loss opposite what moved the piston in the first place. Each type has a unique kind of re-centering technique.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.