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प्रश्न
When we want to use a machine as a force multiplier, which class of lever should we preferably use? Give a simple diagram of such a lever.
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उत्तर
Though we can use either first class of lever or second class of lever, for multiplying force, we should preferably use a second class of lever. This is because the mechanical advantage of the second class of lever is always greater than one. A simple diagram of the second class of lever is shown alongside. The wheelbarrow, the bottle opener, and the mango cutter are some of the practical forms of the second class of lever.
संबंधित प्रश्न
The diagram below shows a lever in use:
- To which class of levers does it belong?
- Without changing the dimensions of the lever, if the load is shifted towards the fulcrum what happens to the mechanical advantage of the lever?
Fig 3.17 below shows a lever in use.
(a) To which class of lever does it belong?
(b) If FA = 80 cm, AB = 20 cm, find its mechanical advantage.
(c) Calculate the value of E.
A lever of length 9 cm has its load arm 5 cm long and the effort arm is 9 cm long.
- To which class does it belong?
- Draw a diagram of the lever showing the position of fulcrum F and directions of both the load L and effort E.
- What is the mechanical advantage and velocity ratio if the efficiency is 100%?
- What will be the mechanical advantage and velocity ratio if the efficiency becomes 50%?
The following belong to which class of lever?
Rowing of a boat
The following belong to which class of lever?
Sugar tongs
The following belong to which class of lever?
Knife
Shears, used for cutting metals and scissors used for cutting clothes are both examples of levers of the first order. However, whereas the shears always have short blades and long handles, the scissors often have blades much longer than the handles. Explain, why this is so?
The diagram shows the use of a lever.
- State the principle of moments as applied to the above lever.
- Which class of lever is this? Give an example of this class of lever.
- If FA = 100 cm, AB = 90 cm, calculate the minimum effort required to lift the load.
The length of a nut-cracker is 12 cm. A nut, when kept at a distance of 4 cm from its fulcrum, requires an effort of 100 gf to crack it. What force will be required to crack the nut without using the nut-cracker?
A lever is used to multiply the force.
