Advertisements
Advertisements
प्रश्न
Name a machine to obtain gain in speed ?
Advertisements
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
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%?
Give three examples for leavers of 1st order.
The following belong to which class of lever?
The Physical balance
The following belong to which class of lever?
A claw-hammer
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.
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?
What is a first-order lever?
A lever is used to multiply the force.
