inertia

Everyday

1. (science) The way an object stays still or keeps moving at the same speed in a straight line until a force changes it. tree →
2. Lack of energy or wish to move or change: laziness. tree →

In the lessons

In science lessons on forces and Newton's first law, and road safety (seatbelts stop your body flying forward). In everyday life, feeling too sluggish to start. Phrases: law of inertia, overcome inertia.

Examples

• When the bus stops suddenly, inertia keeps you moving forward. tree →
• Seatbelts protect you against inertia in a crash. tree →
• A heavy trolley has more inertia than a light one. tree →
• Pull the tablecloth fast and inertia keeps the plates in place. tree →
• After the holiday, inertia kept me on the sofa. tree →
• Newton's first law is called the law of inertia. tree →

Note

Uncountable. Say in-ER-sha. Myth: things do not stop because they run out of force; friction and other forces stop them. More mass means more inertia.