8.3 Terminal Speed * investigation

Question 1

What does any object moving through a fluid experience

Answer 1

A force that drags on it due to the fluid

Question 2

What does the drag force depend on

Answer 2

The shape of the object
Its speed
The viscosity of the fluid which is a measure of how easily the fluid flows past a surface

Question 3

The faster an object travels in a fluid the greater the what

Answer 3

The drag force on it

Question 4

Motion of an object falling in a fluid

Answer 4

• speed of an object released from rest in a fluid increases as it falls
• the drag force on it due to the fluid increases
• the resultant force on the object is the difference between the force of gravity on it (weight) and the drag force
  -As drag force increases the resultant force decreases so acceleration decreases as it falls
• if it continues falling it attains a terminal speed when drag force is equal and opposite to weight
  -Acceleration is then 0 and speed remains constant as it falls

Question 5

What does the top speed a vehicle can reach depend on

Answer 5

The engine power and shape

Question 6

What happens to a stream lined vehicle

Answer 6

Can reach a higher top speed than a vehicle with the same engine power that isn’t streamlined

Question 7

Acceleration of a vehicle in motion

Answer 7

a = Fe - Fr / M

M = vehicles mass
Fe = motive force(driving force) provided by the engine
Fr= resistive force (sum of the drag forces acting on the vehicle)

Question 8

Because drag forces increase with speed the terminal/maximum speed is reached when?

Answer 8

The resistive force becomes equal and opposite to the engine force a=0