Friction = force generated in resistance to
movement
There are two kinds of friction: static and kinetic.
1. Static friction keeps objects from moving as long as the applied force is less than the
static friction. Once the applied force exceeds the maximum static friction, an object
begins to move.
2. Friction remains in play here, but now it slows down a moving object, instead of keeping
one in place. This kind of friction is called kinetic friction.
Friction in relation to rock climbing
In climbing, static friction is created against the rock (or plastic, wood, whatever you
climb on) and our hands, feet, and body. If enough static friction exists, we can move
against it and progress ourselves along a sequence; however, if we generate more
force than the static friction, hands and feet slip, and we fall.
The amount of force friction generated and the type of force required to perform a move
depend on the specifics of the rock type, shape, and texture, as well as your body’s
orientation, environment, and a plethora of other factors.
Some of these factors (often involving the rock), we cannot really control.
Other factors, however, we can control:
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Sweat reduces friction between our hands and rock, so we use chalk to help to dry out
our hands.
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Hand position affects how we can apply a force, so we often test a hand hold different
ways to see which way “feels” best and gives the most secure grip.
The tensile strength of rope helps in trekking.
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The amount of force that a rope can withstand before breaking or failing is
measured by its tensile strength.
When trekking, it's crucial to use a rope with enough tensile strength to make
sure it can withstand the weight and pressures the rope will be subjected to.
This comprises the stresses that may be applied to the rope while it is in use,
such as when it is being used to anchor a climber.
It also includes the weight of the climbers and any equipment that they are
carrying.
Using a rope with insufficient tensile strength can be dangerous, as it may
break or fail unexpectedly. Thus, the rope being used must have proper
tensile strength.