Forces, Matter and Pressure

Forces - A force is a push or pull upon an object resulting from the objectâ&#x20AC;&#x2122;s interaction with another object. - Force can change the size and shape of an object. Forces acting on solids: A Force can stretch, squash, bend or twist an object. It can change the size of an object.

Forces - Hookeâ&#x20AC;&#x2122;s Law Hookeâ&#x20AC;&#x2122;s Law states that the extension of a spring is proportional to the load applied to it, provided the limit of proportionality is not exceeded. It is represented as: F=kx Where, F is the load(force). k is the stiffness. x is the extension.

Pressure Pressure is the force per unit area acting on a surface. It is represented by Pressure = force/area, p=F/A Where, F is force in Newton(N). A is the area in square meter(m^2). P is pressure in Newton per square meter (N/m^2).

Pressure in Fluids In fluids, the pressure does not simply act downwards, it act equally in all directions. Pressure Measurements: a)Manometer: It is an instrument for showing the difference in pressure between two gases or liquids.

Barometer

A barometer is used to measure the atmospheric pressure.

Pressure - Hydraulic System - When the system is in equilibrium, the pressure throughout the system is the same.