Advertisements
Advertisements
Question
Why is this so traveller’s bags have wheels?
Advertisements
Solution
A traveler's bag has wheels so that it can be dragged easily because of reduced friction between the ground and the wheel. Thus, the wheel, a simple machine, helps to decrease the effort to be applied to the load, which is a bag here.
RELATED QUESTIONS
Answer the following.
What do you understand by a complex machine?
Give a reason for the following.
Machines are able to make our work convenient.
The correct relationship between the mechanical advantage (M.A.), the velocity ratio (V.R.) and the efficiency (n) is ______.
Give scientific reason for the following:
Passengers in a bus are pushed backward when it starts suddenly.
Define Efficiency
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?
A cook used a ‘fire tong pair’ of length 32 cm. to lift a piece of burning coal of mass 500 g. If he applies his effort at a distance of 8 cm from the fulcrum, what is his effort? Assume friction etc. to be absent. Also, obtain values of the M.A. and the V.R. of this ‘machine’.
Classify the following as a lever, a pulley and an inclined plane:
Nutcrackers
______ help us to make work easier.
Simple machines makes work easier by trading ______ for force.
