Density and Upthrust

Question 1

What is upthrust?

Answer 1

-The weight of the fluid which is displaced
-Is a force which applies to objects which are partially or fully submerged in a fluid
-This is due to as you go down into the fluid, the greater the weight of fluid so the greater the pressure
-The difference in pressure between the top and the bottom of the object produces an upwards force on it, known as upthrust
-Measured in Newtons

Question 2

How can we influence levels of pressure?

Answer 2

-The weight above it will increase the pressure of the fluid
-Acceleration due to gravity will increase the pressure of the fluid
-Height will decrease the pressure of the fluid

Question 3

How do submarines sink and float?

Answer 3

-They have valves which let water in, increasing its weight allowing it to outweigh upthrust and sink
-They clear the water out, decreasing the weight and balancing it to upthrust, which causes a rise

Question 4

How do you calculate fluid properties?

Answer 4

-Volume of object = Volume of fluid displaced
-Mass of fluid displaced = Density x Volume
-Weight of fluid displaced = mass x acceleration due to gravity
-Volume = Weight of fluid displaced