Terminal velocity is the highest velocity attainable by an object as it falls through a fluid (air is the most common example). It occurs when the sum of the drag force (Fd) and the buoyancy is equal to the downward force of gravity (FG) acting on the object. Since the net force on the object is zero, the object has zero acceleration. In fluid dynamics, an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the fluid through which it is moving. As the speed of an object increases, so does the drag force acting on it, which also depends on the substance it is passing through (for example air or water). At some speed, the drag or force of resistance will equal the gravitational pull on the object (buoyancy is considered below). At this point the object ceases to accelerate and continues falling at a constant speed called the terminal velocity (also called settling velocity). An object moving downward faster than the terminal velocity (for example because it was thrown downwards, it fell from a thinner part of the atmosphere, or it changed shape) will slow down until it reaches the terminal velocity. Drag depends on the projected area, here, the object's cross-section or silhouette in a horizontal plane. An object with a large projected area relative to its mass, such as a parachute, has a lower terminal velocity than one with a small projected area relative to its mass, such as a bullet.

1. TERMINAL VELOCITY
PRESENTED BY
MD. RIAD BADHON
ID :- TE 1707080

2. TERMINAL VELOCITY

3. Introduction
Terminal velocity :- Steady speed achieved by an
object freely falling through a gas or liquid

4. What is Terminal Velocity ?
 When a fluid passes through a another fluid
 It has gravity acceleration
 So that Gravitional force works on it
 But it has to face also a resist force while passing through a fluid

5.  Finally the net force is equal to
zero , Then the fluid passes at
constant velocity
The constant velocity is called
Terminal velocity
• FINALLY THE NET FORCE IS EQUAL TO
ZERO
• SO THE FLUID IS PASSING THROUGH
A CONSTANT VELOCITY
• WHICH IS CALLED UNIFORM
VELOCITY OR TERMINAL VELOCITY

6. Law of falling matter
According to Law of Galileo :- The velocity
of falling objects is increasing 9.8 m/s per
second and the objects fells Gravitional force

7. What happen when fluid passes through
another fluid ?
 It feels Gravitional force
 Having resistance from another fluid
 having Viscous force to the opposite direction
 Suddenly it loses its acceleration

8.  So that Net force
becomes zero
 Then it gets constant
velocity

9. Can we call terminal velocity as Uniform
velocity ?
 If we take independent
variable in x axis which is
time
 And if we take dependent
variable in y axis as
velocity
 We can this type of graph

10.  The trigonometrical tangent of the graph represents the
acceleration
tanϴ = V/t m/s²
 Here velocity is increasing ,one time the curve becomes to parallel
to the x axis
 It shows the velocity remains same while time is changing
 So we can call is uniform velocity

12. Rain is falling with Terminal velocity

13. Explanation
 If rain does not carrying terminal velocity when it falls
 It falls like a bullet because according to Galileo’s law ,its velocity is
increasing 9.8 m/s per second and the distance of earth and cloud
is about 4 to 5 miles up
 Do you imagine ,what does the velocity became while it is falling

14.  Rain is to gain Gravitional force and also has to resist the viscous
force
 At last the net force is equal to zero
 And the acceleration is also zero
 So the Rain water gain terminal velocity

16. Application in Real life
 The parachute has a very large surface area and drag coefficient
and a relatively small mass
 so it experiences much higher air drag forces than you would
without a parachute
 Falling of Rain

17. Conclusion
Terminal velocity is a blessing of God, we should know physics
so that we can know about the real reason about various topics

18. Do you have any question ?

19. Thank you