⇒ A scalar quantity has one size e.g. a mass of 2kg

⇒ A vector quantity has both size and direction e.g. a 5N force acting downwards

⇒ The size of a turning effect is called torque or a turning moment

⇒ Turning moment = force applied x perpendicular distance from the pivot

⇒ Newton's first law of motion states that when no force acts - or when balanced forces act on an object - that object will remain at rest or continue to move in a straight line at a constant speed

⇒ A scalar quantity is one that only has size e.g. mass, temperature, energy, distance, speed, time

⇒ A vector quantity is one that has magnitude (size) and direction e.g. force, acceleration, velocity, and displacement

⇒ A resultant vector is the vector that results from adding two or more vectors in a vector sum (e.g. resultant force or resultant displacement)

⇒ Also see our notes on:

• The Addition of Vectors
• The Resolution of Vectors
• Turning Moments