04: Explain why ball is always in neutral equilibrium.
05. Explain the following:
1. Traffic cones have wide bases and narrow tops.
2. ten pin bowling pins have narrow base heavy top
3. on a double decker bus passenger are not allowed to stand on the upper deck
4. are half empty milk bottle is more stable than a full one
Answers
Ans:4 - In the case of a neutral equilibrium, a body remains in any position, which may be given to it. That is, on disturbing the body; its center of gravity is neither raised nor lowered from its original position, but always remains at the same height. For example, if a ball is in motion it is in neutral equilibrium.
Ans:5 -
1.It has a wide base so the center of gravity acts on small area so preventing any unnecessary fall.
2.We know that pressure is inversely proportional to area so area decreases to produce more efficiency
3. In a double Decker bus passengers in the upper deck are not allowed to travel standing, because if they stand the center of gravity of the system of the bus and all the passengers shifts to some more height.It affects the stability which leads the bus with the passengers to fall down.
4.Then, the second one is the most stable one. The bottle is circa half full, thus the center of gravity is below the middle. Thus most of the mass is in the lower half, since the liquid is heavier than the air in the upper half.