(ii) The largest mass, m of a stone that can be moved by the flowing river depends on the velocity of flow v, the density p of water, and the acceleration due to gravity g. Show that the mass, m varies to the sixth power of the velocity of flow.
(b) (i)List down two limitations of projectile motion.
(ii) A body projected from the ground at the angle of600is required to pass just above the two vertical walls each of height 7m. If the velocity of projection is 100ms-1, calculate the distance between the two walls.
(c) A fireman standing at a horizontal distance of 38m from the edge of a burning storey building aimed to raise streams of water at an angle of 600into the first floor through an open window which is at 20m high from the ground level. If water strikes on this floor 2m away from the outer edge,
(i)sketch a diagram of the trajectory.
(ii)At what speed will the water leave the nozzle of the fire hose?
(b) (i)State the principle of conservation of angular momentum.
(ii) A horizontal disc rotating freely about a vertical axis makes 45 revolutions per minute. A small piece of putty of mass 2.0 x 10-2 kg falls vertically onto the disc and sticks to it at a distance of 5.0x10 m from the axis. If the number of revolutions per minute is reduced to 36, calculate the moment of inertia of the disc.
(c)The amplitude modulated (AM) broadcast band ranges from 450 to 1200 kHz. If each station modulates with audio frequencies up to 5.5 kHz, determine the: (i) bandwidth needed for each station (ii) total bandwidth available.
(ii) List down three sources of earth's magnetism.
New Roman'; font-size:14pt;">(b) A large explosion at the earth's surface creates compressional (P) and shear (S) waves moving with a speed of 6.0kms-1 and 3.5 kms-l respectively. If both waves arrive at the seismological station with 30 seconds interval, calculate the distance measured between seismological station and the site of explosion.