Page 80 - Physics Form 5 KSSM_Neat

Relationship between the Equilibrium of Forces and the State of Floatation of
an Object in a Fluid
When an object is submerged in a fluid, the object experiences two forces: the weight of the
object, W due to gravity and the buoyant force, F due to the fluid displaced. The state of
B
floatation of the object is determined by the relative magnitudes of the two forces.
Figure 2.31 summarises the state of floatation of an object in a fluid.
KEMENTERIAN PENDIDIKAN MALAYSIA

State of floatation of an object
in a fluid

Buoyant F
B
force, F
B
Buoyant force, F
B
Buoyant force, F
B
W a a
Weight, W
Weight, W
Weight, W

W = F W  F W  F
B B B

Resultant force = 0 Resultant force Resultant force
downwards upwards

Balanced force Unbalanced force Unbalanced force

Object moves
Object is downwards with an Object moves upwards
stationary acceleration, a with an acceleration, a

Figure 2.31 State of floatation of an object in a fluid

70 LS 2.5.2