a. What is the meaning of weight?
~ Force of gravity acting on the object
b.(i) Using Diagram 9.1, compare the weight of the boy and his father, the volume of the
water displaced and the buoyant force acted on both of them.
~ The weight of the father is higher than the weight of the boy.
~ The volume of the water displaced by the father is bigger than the volume water
displaced by the boy.
~ The buoyant force that acts on the father is greater than that on the boy.
(ii) State the relationship between the buoyant force and:
(a) The volume of water displaced
~ When the volume of water increases, the buoyant force increases.
(b) The weight of water displaced
~ When the weight of water displaced increases, the buoyant force increases.
(iii) Name the physics principle involved.
~ Archimedes' principle.
c. Diagram 9.2 shows what happens when a wooden block is held above the water surface
and the released into the water.
~ When the wooden block is submerged in water, the buoyant force is greater than its
weight.
~ The buoyant force pushes the block upwards.
~ This occurs until the block reaches the surface when the weight of water displaced.
d. The State Forestry Department is going to organize a competition. As a team leader,
you are required to give some suggestions to design a raft which can accommodate 15
participants and be able to move quickly in water.
Using your knowledge of motion, forces and properties of materials, state and explain
the suggestions based on the following aspects:
(i) The shape of the raft.
~ Stream line shape
(ii) The material used for the raft.
~ Material used is light like bamboo
(iii) The size of the raft.
~ The size is larger
(iv) The design of the raft
~ Tie the bamboo in layers.
