8.3 Terminal speed

Question 1

What 3 things does drag depend on?

Answer 1

» Shape of the object
» Its speed
» The viscosity of the fluid

Question 2

What is viscoscity?

Answer 2

» A measure of how easily the fluid flows past a surface

Question 3

What happens when drag force increases?

Answer 3

» Resultant force decreases
» Acceleration decreases

Question 4

What is terminal speed?

Answer 4

» When the drag force on it is equal and opposite to its weight
» Acceleration is then 0
» Speed remains constant

Question 5

What is the intial acceleration when an object falls?

Answer 5

» g
» Speed is zero, therefore drag force = 0

Question 6

What happens at the terminal speed?

Answer 6

» The potential energy of the object is transferred as it falls, into iternal energy of the fluid by the drag force

Question 7

What is the magnitude of the acceleration at any instant?

Answer 7

» The gradeint of the speed-time graph

Question 8

What is the motive force also known as?

Answer 8

» The driving force - provided by the egine