Advertisements
Advertisements
प्रश्न
Answer the following.
What is a machine?
उत्तर
Tools and objects that help us to perform the same amount of work with much less effort than if we did the work manually, are called machines.
Example: lever, hammer, knife, etc.
APPEARS IN
संबंधित प्रश्न
What care would you take to increase the life span of a machine which you use?
Give two examples of inclined plane where it is used to raise a heavy load with less effort ?
Give scientific reason for the following:
Passengers in a bus are pushed backward when it starts suddenly.
Define Mechanical advantage
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?
Write an expression to show the relationship between mechanical advantage, velocity ratio, and efficiency for a simple machine.
Give an example of the following use of a machine to obtain gain in 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.
Classify the following as a lever, a pulley and an inclined plane:
A knife
Why is this so traveller’s bags have wheels?