Question
Give three examples to illustrate that friction is a necessary evil.
✓
Answer
The examples to illustrate that friction is a necessary evil are:
- If friction were absent, we would not be able to walk.
- Friction is necessary to burn a matchstick.
- It is due to friction that we can write on board by chalk.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The mechanical advantage of a machine is 5. How much load it can exert for the effort of 2 kgf?
The tip of a drawing pin has an area of $0.01 \ mm^2$. Find the pressure exerted by it if a force of $20\ N$ is applied on it.
→Fig. 2.14 shows four identical wooden rods, placed side by side, such $t$ hat their total thickness is 5 cm . Find the thickness of a single rod, correct to two decimal places.
→Magnets are used to close the doors of a refrigerator tightly.
In a machine, an effort of 10 kgf is applied to lift a load of 100 kgf. What is its mechanical advantage?
Identify the agent exerting the force, the object on which the force is acting and the effect of the force in the following situation
Squeezing out the juice from an orange.
Squeezing out the juice from an orange.
Calculate the mechanical advantage of a crowbar of length 240 cm if its fulcrum is situated at a distance of 40 cm from the load.
Boats and ships have streamlined shapes.
Water cycle is an example of interconversion of states of water. Explain.
Where is pressure greater : 5 m below the surface of the sea or 10 m below the surface of the sea ?