WA3 type shi

What is centre of gravity?

The centre of gravity is an imaginary point where the entire weight of the object seems to act on

What is pressure?

Pressure is the force acting per unit area

Formula for pressure

Pressure = force over area

What is the Pascal’s Principle?

The Pascal’s Principle states that if pressure is applied to an enclosed liquid, the pressure is transmitted uniformly to all parts of the liquid

Formula for density

Density = mass over volume

Pressure in liquid at any point below air-liquid surface

Pressure = product of height (m) , density (kg/m3) and gravitational field strength (N/kg)

Pressure of gas in manometer

Pressure = product of height, density, gravitational field strength + atmospheric pressure

Formula for energy in kinetic store

Energy in kinetic store = ½ of product of mass and speed squared

Formula for gravitational potential store

Energy in gravitational potential store = product of mass, gravitational field strength, and height

What is work done

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

What is power

Power is defined as the work done or energy transferred per unit time

Formula for power

Power = work done over time taken (s) or energy transferred over time taken

Formula for efficiency

Efficiency = useful energy input / total energy input x 100%

What is the principle of conversion of energy

• states that energy cannot be created or destroyed

• energy can be transferred from one store to another

• total energy of an isolated system is constant

What is density?

Mass per unit volume