Activity 8.4 – Science Form 2 Chapter 8

Activity 8.4:
Aim: To determine buoyant force.

Materials: Glass bottle lid, rubber stopper, squash ball, plasticine and string

Apparatus: 250 ml beaker and spring balance

Instruction
1. Hang a glass bottle lid at the end of a spring balance as shown in Photograph 8.7 (a).

2. Record the actual weight of the glass bottle lid, W₁.

3. Fill 250 ml of water into a beaker.

4. Put the bottle lid into the water as in Photograph 8.7 (b).

5. Record the apparent weight of the bottle lid, W₂.

6. Calculate the buoyant force, F.

7. Repeat steps 1 to 6 using a rubber stopper, squash ball and plasticine.

8. Put the bottle lid, rubber stopper, squash ball and plasticine into the water. Observe whether they submerge or float.

9. Record your observation in the table below.



Question
1. What is the relationship between the buoyant force of an object and the condition of the object?

Answer:
When buoyant force is equal to the weight of the object, the object floats.
When the buoyant force is less than the weight of the object, the object submerges.