UNEB UCE PHYSICS 2025 ITEM 3

During dry season , a sailor in an ocean embarked on a journey to transport fish to a certain island for packaging . The sailor was not sure of the direction to take in order to reach the destination (island) safely without getting lost. The sailor contacted her friend who was already at the destination. In a bid to help the sailor her friend sent a Google map link and guided the sailor on how to use it. The sailor followed it up to reach the destination (island) without getting lost . However the sailor did not know how the Google map works. On arrival at destination(island) , the sailor noticed that the level of water started rising in the ocean at night ; where the wave carried large volumes. This could cause any sailor’s boat to become unstable and eventually capsize. The sailor wondered whether there are benefits of such rising water levels, to the communities living in such around such water bodies, during dry season. while at the island , the sailor also noticed that , the island is equipped with an automatic security light system that switches on at night and off during day time ,as seen in figure 1 The sailor was amazed by the automatic lighting system. The sailor wanted to be educated on these occurrences or observations made. You have been contacted to be of help to the sailor. Task Help the sailor to understand: (i) why the water behaved the way it did. (ii) how the application sent by her friend works. (b) Educate the sailor on how the security light system in the circuit , in figure 1 works (include the truth table). (c) Explain any two benefits the sailor needs to know about the water behavior observed.