A stone of mass 20g is released from a catapult whose rubber is stretched through 5cm.  If the force constant of the rubber is 200Nm\(^{-1}\), calculate the speed with which the stone leaves the catapult.

(a) The diagram above illustrates a projectile motion. Identify each of the physical quantities labeled P, β, H and R.               

                                                 
(b) Write an equation to show the relationship between P, g and Rmax’ where g is the acceleration due to gravity and Rmax is maximum R.                    

State three observable phenomena in which waves behave like a particle.

List three magnetic elements that determine the earth’s magnetic field at a point.  

Explain each of the following terms as used in Electronics.

(a)  free electrons;

(b)  holes.