Question

Explain why? A. A sharp knife cut objects more effectively than a blunt knife B. The tip of sewing needle is sharp C. A wide belt is provided over the wheels of an army tank.​

Answer 1

Answer :

• a) A Sharpe knife than a blunt knife because the area with which the knife gets it contact with the object to be cut is way lesser in a sharp knife. Due to this the pressure applied increses and the thus cuts better than a blunt knife
• b) The tip of a sewing needle is Sharpe so that it's able to pierce through easily without a greater effort. Sharper something is, the lesser would be the area of contact and so higher the pressure
• c) Army tanks are very heavy vehicle so if they have a narrow belt then due to the high weight it would go into the soil and so as the belts have a higher area of contact the pressure reduces thus avoiding this situation.

Answer 2

Answer:

Lesser the area, larger the pressure for the same force applied. Therefore it is easier to cut with sharp knives than blunt ones, with same force