Final answer:
To tighten the brakes by adjusting the nut, the adjusting nut should be turned clockwise, as this is the direction that increases tightness by applying torque in mechanical systems.
Step-by-step explanation:
To tighten the brakes on a vehicle by adjusting the nut, the adjusting nut should be turned clockwise. This convention is based on the common mechanical principle that turning a nut clockwise tightens it, while counterclockwise loosens it. In the context of applying torque with a wrench, to tighten a fixing such as brake calipers, you would need to apply a force that creates torque in the clockwise direction. This is because torque is a measure of the turning force on an object such as a nut or bolt and is calculated as the product of the force applied at a distance from the pivot point, or in this case, the center of the nut.
As an example, if a mechanic is required to tighten a cylinder head bolt with a specified torque of 62.0 N.m, and they use a wrench with a length of 0.20 m, the mechanic must apply a perpendicular force calculated by the torque divided by the length of the wrench. Using the relationship torque = force × distance, one can find the necessary force to apply.