S2 2026 Chapter 9 - Forces

1 m/s = ___km/h

3.6

Formula for gravitational force or weight

W = mg

SI unit for gravitational force or weight (W)

N (Newton)

SI unit for mass, m

kg

SI unit for gravitational field strength, g

N/kg

SI unit for force

N (Newton)

Definition of friction

Friction is the force that opposes motion between two surfaces in contact.

Definition of elastic force

Elastic force is the force acting on a stretched or compressed elastic object to return it to its original shape.

Definition of magnetic force

Magnetic force is the force exerted between a magnet and another magnetic material.

Types of contact forces

Friction, elastic force

Types of non-contact forces

Gravitational force, magnetic force

Definition of weight

Weight is the measure of the gravitational force acting on an object.

SI unit of weight is the same as for…

force

Definition of mass

Mass is the amount of matter in an object.

Formula for pressure

Pressure = Force/Area

SI unit for pressure

N/m2

SI unit for area

m2

Formula for work done

Work done = Force x distance moved in the direction of the force

Definition of work done

Work done by a force on an object is the product of the force and the distance moved by the object in the direction of the force.

SI unit of Energy

J (Joule)

Energy cannot be ___ or ____ but can be ____ from ____ to ____. The ___ energy in an ___ ___ is ___.

Energy cannot be created or destroyed but can be converted from one form to another. The total energy in an isolated system is constant.