Physics 5.5.4

Question 1

What is ‘Upthrust’?

Answer 1

Upthrust is a Force that Pushes Upwards on an Object Submerged in a Fluid.

Question 2

Upthrust always Acts in the ___ Direction to the Object’s ___.

Answer 2

Opposite, Weight.

Question 3

What does the Size of the Upthrust depend on? (2)

Answer 3

-The Density of the Fluid.

-The Volume of the Fluid.

Question 4

The Denser the Liquid, the ___ the Upthrust it will Exert on an Object.

Answer 4

Greater.

Question 5

What is Upthrust due to?

Answer 5

The Difference in Pressure between the Top & the Bottom of the Submerged Object.

Question 6

Whether an Object Sinks or Floats depends on the… (2)

Answer 6

-Upthrust.
-Density.

Question 7

When will an Object Float & Sink, in terms of Upthrust? (2)

Answer 7

-If the Upthrust on an Object is Equal to or Greater than the Object’s Weight, then the Object will Float.

-If the Upthrust is Smaller than the Weight of the Object, then the Object will Sink.

Question 8

When will an Object Float & Sink, in terms of Density? (2)

Answer 8

-If the Object is Less Dense than the Fluid, it will Float.

-If the Object is More Dense than the Fluid, it will Sink.

Question 9

Why do Objects that are Denser than the Fluid Sink?

Answer 9

Because if the Density of the Object is Greater than the Density of the Fluid, the Object can never Displace enough Fluid to Create an Upthrust that will hold its Weight up, & so therefore Sinks.