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प्रश्न
Which machine will you use to do the following work? Write their type.
To remove the lid of a tin.
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उत्तर
To remove the lid of a tin, a tin opener or can opener, which is a second-order lever machine, is used.
संबंधित प्रश्न
Fill in the blank:
The useful work done by an actual machine is always ............ than the work done on the machine.
What do you understand by a machine?
State the kind of lever which always has mechanical advantage less than 1. Draw a labelled diagram of such a lever.
Fig show a system of four pulleys. The upper two pulleys are fixed and the lower two are movable.
(i) Draw a string around the pulleys. Also show the place and direction in which the effort is applied.
(ii) What is the velocity ratio of the system?
(iii) What is the mechanical advantage of the system?
(iv) What assumption do you make in arriving at your answer in part (iii)?
Define mechanical advantage.
Define velocity ratio.
Fig. shows a spade. It is being used to lift soil weighing 30N from the ground.
(a) Mark the direction of the least force on the handle necessary to keep the spade balanced.
(b) Calculate the least force on the handle necessary to keep the spade balanced (the weight of the spade is negligible).
(c) If the left hand was move towards the soil on the spade, would the force on the handle necessary to keep the soil balance the greater or less? Give a reason for your answer.
(d) To which class of lever does the spade belong?
Give an example of the following use of a machine to change the direction of force.
A uniform metre scale is kept in equilibrium when supported at the 60 cm mark and a mass M is suspended from the 90 cm mark as shown in the figure. State with reasons, whether the weight of the scale is greater than, less than or equal to the weight of mass M.
Name the levers mentioned in the following passage. Identify the fulcrum, load, and effort of each and say which type of lever it is.
Ravi and Savita sit on a seesaw in a garden. In the meantime, a gardener is trimming trees in the garden. He puts the leaves and other garbage in the wheelbarrow. Later, Ravi gets thirsty and he buys lemon sherbet. The sherbet seller cuts the lemon and squeezes it using a lemon squeezer. He puts small pieces of ice in the glass with the help of the tongs.
