What is inertia? Explain the types of inertia with examples.

1. 1 · Define inertia in one line. Inertia is the natural tendency of a body to resist any change in its state of rest or of uniform motion. Mass is its measure.
2. 2 · Inertia of rest. A body at rest tends to stay at rest. Example: a bus starts suddenly and standing passengers fall backward.
3. 3 · Inertia of motion. A moving body tends to keep moving. Example: a bus stops suddenly and passengers fall forward; an athlete runs before a long jump.
4. 4 · Inertia of direction. A moving body tends to keep its direction. Example: on a sharp turn, passengers are pushed sideways.
5. 5 · Real-life link. Seat belts protect us from inertia of motion; shaking a mango tree drops ripe fruit (inertia of rest).
6. 6 · Close in one line. Newton's first law is called the law of inertia because it describes this property.

Scoring tip: Give one clear example for each type. Examiners look for the word 'tendency' and the link to mass.