fluid mechanics - lesson 12

Question 1

define buoyancy

Answer 1

refers to the upward force that keeps things afloat

Question 2

what is Archimedes’ principle?

Answer 2

the buoyant force is equal to the weight of the fluid displaced by the object

when forces of objects mass are = or less than buoyancy forces, the object will float

when forces of objects mass are greater than buoyance forces, the object will sink

Question 3

what is positive buoyancy?

Answer 3

displaces a volume of liquid equal to or greater than its weight and will float

makes it easier to streamline which decreases drag on a swimmer

Question 4

what is negative buoyancy?

Answer 4

Displaces a volume of fluid less than its own weight and sinks

Question 5

what is neutral buoyancy?

Answer 5

When an object will neither sink or float but remains suspended in the fluid.

Question 6

how does buoyancy affect a swimmer?

Answer 6

swimmer with positive buoyancy experiences less fluid resistance than a swimmer who is less buoyant

Question 7

what are lift forces?

Answer 7

force applied by a fluid that acts perpendicular to the direction of fluid flow

Question 8

how are lift forces created?

Answer 8

by different pressures on opposite sides of an object due to fluid flow past the object

objects want to move from an area of high pressure to low pressure resulting in an upwards (water) or downwards (on land) lift force being created

Question 9

what is the effect of long distances for airflow to travel?

Answer 9

faster airflow and decreased pressure

Question 10

what is the effect of shorter distances for airflow to travel?

Answer 10

slower airflow and increased pressure