A lever is shown below.

(a) Identify the type of lever.

(b) Calculate its mechanical advantage.

Two bodies A and B have same kinetic energies. Compare their velocities if mass of A is four times the mass of B.

Two copper wires A and B are of the same thickness and are at the room temperature. If the length of A is twice the length of B then :

(a) Compare their resistances

(b) Compare their resistivity

(a) Name the waves used for echo depth sounding.

(b) Give one reason for their use in the above application