Question

Give reason for the following:

a) Cutting tools have sharp edges

b) Vehicles are equipped with wheels

b) Birds and fishes have streamlined body​

Answer 1

Cutting tools have sharp edges

The cutting edges of tools like blades, knives etc., are provided with sharp edges to cut the things easily as the sharp edges has small area on which the force is applied, hence more pressure is applied.

Vehicles are equipped with wheels

Why are the wheels of vehicles are provided with mudguards? Answer: When the wheel rotates at a high speed, the mud sticking to the wheel flies off tangentially, this is due to inertia of direction. In order that the flying mud does not spoil the clothes of passersby, the wheels are provided with mudguards

Birds and fishes have streamlined body

Birds have streamlined body so as to reduce the air resistance during flying. Whereas fishes have streamlined body so as to reduce friction in water and help them to move faster