The density of an object is defined as its mass per unit volume. Mass is measured directly using a digital balance. Volume is measured either using measurements taken with a ruler, digital calliper of micrometer (for regular solids), or by displacement (for irregular...

# 3.2 Forces in action

## DynamicsDynamics

Net force is the product of mass and acceleration. The unit of force is newtons (N). f = m × a. The mass of an object is absolute – it is constant for a specific object or particle. However, the magnitude of weight is variable; it depends on gravitational field...

## Motion With Non-uniform AccelerationMotion With Non-uniform Acceleration

Drag is the frictional force experienced by an object travelling through a fluid. Its magnitude depends on several factors, including the speed of the object, the shape (cross-sectional area) of the object, the roughness or texture of the object, and the density of...

## EquilibriumEquilibrium

The moment of a force is the turning effect of a force about some axis or point. It is defined by: Moment = force x perpendicular distance from the line of action of force from the pivot Moment = Fx The SI unit for the moment of a force is Nm. The principle of...