What are the different types of levers and their uses
Answers
Answer:
Jasmin leave and mango leave , curryleaf ,
neem leaf .etc
NCERT based Answer for Class 11 Biology Students
Lever: A lever is an object that can multiply mechanical force (effort) or resistance force (load). It is one of the most basic forms of a machine, which helps lift heavy objects with much less effort.
3 Components of a Lever:
(i) Load is the object you are lifting.
(ii) Fulcrum is the joint at which the lever pivots. Bone joints in our body act as fulcrum.
(iii) Effort is the force applied to make the object move. Muscles apply effort.
Three Classes of Levers: The location of these 3 components determines the lever class.
1st Class Levers : The fulcrum is located between the applied force and the load. Examples are a seesaw and scissors.
1st Class Levers in the Human Body: These are very few in the human body. One example is the joint between the head and the first vertebra. The weight (resistance) is the head, the pivot is the joint, and the muscular action (force) come from the posterior muscles attaching to the skull.
2nd Class Levers: The load is situated between the fulcrum and the force. Examples are wheelbarrow and nutcracker.
2nd Class Levers in the Human Body: An example of a second-class lever is found in the lower leg when someone stands on tiptoes. The axis is formed by the metatarsophalangeal joints (joints between phalanges and metatarsals), the resistance is the weight of the body, and the force is applied to the heel by shank muscles through a tendon.
3rd Class Levers: The force is applied between the fulcrum and the load. Examples are a pair of tongs or tweezers and a fishing rod.
3rd Class Levers in the Human Body: There are numerous third-class levers in the human body. One example can be illustrated in the elbow joint. The joint is the axis (fulcrum). The resistance (weight) is the forearm, wrist, and hand. The force is applied by the biceps muscle through a tendon.
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