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प्रश्न
Name a machine to obtain gain in speed ?
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उत्तर
To obtain gain in speed: when a pair of scissors is used to cut the cloth, its blades move longer on cloth while its handles move a little.
संबंधित प्रश्न
Draw a diagram of a lever which is always used as a force multiplier. How is the effort arm related to the load arm in such a lever?
A man uses a crowbar of length 1.5 m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance 1 m from his hand.
- Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions.
- State the kind of lever.
- Calculate:
- load arm,
- effort arm,
- mechanical advantage and
- the effort needed.
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?
The Physical balance
The following belong to which class of lever?
Pliers Tools
The following belong to which class of lever?
Sugar tongs
The following belong to which class of lever?
Nutcracker
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?
Draw a labelled sketch of a second class lever. Give one example of such a lever.
In the following diagram of a wheelbarrow, mark the fulcrum (F) and indicate the directions of load (L) and effort (E) with arrows.
What class of lever is it? Give one more example of the same class of lever.
