The tube of the barometer is attached to one end of a steel yard or balanced lever, which carries at the other end a counterbalance weight and a small pointer, which is reflected in a mirror.

Key fact When a lever is balanced it has equilibrium - the load is balanced on either side. A crowbar is an example of a first order lever that puts the load closer to the fulcrum - this gives it ...

Key fact When a lever is balanced it has equilibrium - the load is balanced on either side. A crowbar is an example of a first order lever that puts the load closer to the fulcrum - this gives it ...