P11.4 Upthrust and flotation Flashcards
1
Q
What is upthrust?
A
The upward force on the body created by water
2
Q
How can you investigate upthrust?
A
Use a newton-meter to weight a metal object in air - then repeat the test by weighing the same object when it is completely in water
3
Q
Why does the water level in a water container rise when an object is lowered into the water?
A
This is because the object displaces some of the water
4
Q
What happens when an object is lowered into water?
A
Bigger the volume of water displaced so the bigger the upthrust
5
Q
When does the object float?
A
When its weight is equal to the upthrust
6
Q
When does the object sink?
A
When its weight is greater than the upthrust
