Types of Levers
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The pivot is the place where your skull meets the top of your spine. Your skull is the lever arm and the neck muscles at the back of the skull provide the force (effort) to lift your head up against the weight of the head (load). When the neck muscles relax, your head nods forward.For this lever, the pivot lies between the effort and load. A see saw in a playground is another example of a Class 1 lever where the effort balances the load
Class 1 lever – nod your head
The pivot is at your toe joints and your foot acts as a lever arm. Your calf muscles and Achilles tendon provide the effort when the calf musclecontracts. The load is your body weight and is lifted by the effort (muscle contraction).The load is between the pivot and the effort (like a wheelbarrow).
The effort force needed is less than the load force, so there is a mechanical advantage. This muscular movement at the back of your legs allows you to move your whole body a small distance.
Class 2 lever – stand on tip toes
The pivot is at the elbow and the forearm acts as the lever arm. The biceps muscle provides the effort (force) and bends the forearm against the weight of the forearm and any weight that the hand might be holding.The load is further away from the pivot than the effort. There is no mechanical advantage because the effort is greater than the load. However this disadvantage is compensated with a larger movement – a small contraction of the biceps produces a large movement of the forearm. This type of lever system also gives us the advantage of a much greater speed of movement.Many muscle and bone combinations in our bodies are of the Class 3 lever type.
Class 3 lever – bend your arm
Bending your arm is what class lever
Class 3 Lever
Standing on tip toes is what kind of lever
Class 2 Lever
Noding your head or a see saw is what kind of lever
What would you like to do?
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