Section 1 c) Key Words

Acceleration: The rate at which the velocity of an object increases. A vector quantity.

Centre of Gravity: The point at which the mass of the object is equal in all directions; the point count be put on a pinpoint and it would not move as all the forces are balanced.

Drag: A force that opposes motion, for example friction or air resistance.

Elastic Limit: The point at which an elastic object is permanently stretched. Beyond this point Hooke's law cannot be applied.

Force: A push or pull on an object due to its interaction with another object, resulting in change of shape, speed, or direction.

Friction: A force opposing motion- happens between two solids e.g. a ball rolled on a carpet.

Hooke's Law: Hooke's law says that extension is proportional to force in an elastic object. As the force applied increases, the extension will increase proportionally.

Magnitude: Size

Mass: How much of an object there is; it has the same value anywhere in the universe

Momentum: How fast an object is going multiplied by its mass- its 'quantity of motion'

Newton's Laws of Motion: 1st law- balanced forces mean no change in velocity
2nd law- a resultant force means acceleration
3rd law- every force has an equal force acting in opposition to it.

Scalar: A quantity that has magnitude (size) but no direction. e.g. mass, distance, speed

Terminal Velocity: When the vertical forces on an object are balanced resulting in a constant speed and no acceleration.

Vector: A quantity that has both magnitude (size) and direction. e.g. weight, displacement, velocity, force

Weight: The force that gravity exerts on matter calculated by multiplying mass by gravity (which is 10 on Earth)