Advertisements
Advertisements
प्रश्न
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)?
उत्तर
(i) Correct winding of rope around pulleys, load and effort is as shown:
(ii) Since there are four strings in the block and tackle system,therefore, velocity ratio of the system is V.R = n = 4.
(iii) M.A = L/E
here, L = 4T, E = T
M.A = `(4"T")/"T" = 4`
(iv) The assumptions made are movable pulleys are weightless and efficiency of the system is 100%.
APPEARS IN
संबंधित प्रश्न
What do you understand by a machine?
Answer the following.
What do you understand by a complex machine?
A crowbar of length 120 cm has its fulcrum situated at a distance of 20 cm from the load. Calculate the mechanical advantage of the crowbar.
Define Mechanical advantage
Can a simple machine act as a force multiplier and a speed multiplier at the same time?
Classify the following as a lever, a pulley and an inclined plane:
Scissors
The ______ in the centre, the ______ on one side and the ______ on the other side make a lever of the third order.
Which machine will you use to do the following work? Write their type.
To cut vegetables.
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.
Simple machines makes work easier by trading ______ for force.
