Answer the following:
A. Why friction is called a necessary evil?
B. Explain why objects moving in fluids must have a special shape? [5 MARKS]
Answer the following:
A. Why friction is called a necessary evil?
B. Explain why objects moving in fluids must have a special shape? [5 MARKS]
Part A : 2 Marks
Part B : 3 Marks
A. Friction is necessary in everyday life for us to start moving, playing and various activities. At the same time it also hinders motion and heats up machineries and creates wear and tear. So it’s necessary evil.
B. When objects move through fluids, they have to overcome the friction acting on them. Efforts are therefore made to minimize the friction so objects are given special shapes. Idea of such shapes come from the body structure of birds and fishes which have to move about in fluids all the time. Such shapes are called streamlined. Giving such shapes to the ships, plane and cars is called streamlining.
Part A : 2 Marks
Part B : 3 Marks
A. Friction is necessary in everyday life for us to start moving, playing and various activities. At the same time it also hinders motion and heats up machineries and creates wear and tear. So it’s necessary evil.
B. When objects move through fluids, they have to overcome the friction acting on them. Efforts are therefore made to minimize the friction so objects are given special shapes. Idea of such shapes come from the body structure of birds and fishes which have to move about in fluids all the time. Such shapes are called streamlined. Giving such shapes to the ships, plane and cars is called streamlining.
