Summary Edexcel A Level Physics Student Book 1 - Unit 4 - Materials

Materials

, ① Upthrust
This is the upward force acting on an
object in a fluid due to different
pressures beingexerted on it .




Ap =
liquid pressure
& :
fluid density
Ap =
pgAh g = gravitational field strength
Bh :
height




Archimedes' principle states that the upthrust experienced by an object
is equal to the weight of the fluid it displaces.

Upthrust =
weight of fluid displaced
o= density of fluid
V volume of displaced
-Upthust Vg
=

=
fluid

9 = gravitational field strength




·
If object an is floating in a liquid ,
its weight mustesual its

upthrust .




② Stoke's Low
The resistive force experienced by an object moving
in a fluid is

known as the visions
drag force
.




Stone's haw states that the visions dragforce (F) ca be calculated by :
7 =
viscosity of fluid
E F =
Gayr ~ =

~ =
radius of object
terminal velocity of object


-
.
2 (Psolid-Pfinid) grh
i
=

9v