Locomotion and Flight

1. Locomotion and Flight

2. Locomotion

3. Moving on Land • Animals generate internal forces to contract muscle to move. This causes external force that is applied to their surroundings. • The external force that is exerted on the ground causes an equal and opposite force from the ground.

4. Newton’s Laws of Motion • Newton’s First Law of Motion • An object in motion stays in motion unless acted upon by an outside force • Newton’s Third Law of Motion • For every action there is an equal and opposite reaction

5. Motions of Animals that can be changed • Speed up • Slow down • Change direction

6. Requirements of Changing Motion • A force is required to change the motion of an animal • The earth provides a force in the opposite direction of the force applied by the animal

7. Forces Exerted- Walking • If an animal is walking forward, it is exerting a force opposite of the direction to its movement, or backward • The earth is then exerting a force in the direction of the animal’s movement, or forward

8. Forces Exerted Direction of Movement Forces exerted by animal Forces exerted by earth

9. Forces Exerted- Slowing Down • The Earth provides a force in the direction opposite to the animals original movement • If an animal is running forward and begins to slow down, • the animal exerts a force in the direction that it is moving • The earth exerts a force in the opposite direction that the animal is moving

10. Forces Exerted- Slowing Down Forces exerted by Earth Forces exerted by Animal to slow down

11. Newton’s 3rd Law and Movement on Land • In order for a human or animal to walk on land a force is needed. As a step is taken, a force is exerted on Earth. The earth exerts a force in return and in the opposite direction of the original force. • When the direction of animal changes the earth exerts an equal and opposite force in return • Equal and opposite forces is described in Newton’s 3rd law

12. Physical Characteristics and an Animals Ability to move • As leg length increases, stride length also increases. • Stride rate is also related to leg length • Organisms with shorter limbs must take more strides per unit of time than organism with longer limbs • Shorter limbs= longer time it takes to cover a certain distance

13. Moving in Water • Drag Force- the resistance force due to a fluid • Factors that affect drag force • Velocity • Surface area • Smoothness of surface • Density of surface • Shape of the object/animal • Movement has both speed and direction known as Velocity

14. Drag Force in Water • When an object/animal is moving through the water there is LESS DRAG FORCE when it is moving SLOWLY • When an object/animal is moving through the water there is MORE DRAG FORCE when it is moving QUICKLY

15. Shape Affecting Movement in Water • As the surface area increases, the drag force encountered increases, which allows for faster movement through the water

16. Forces of Motion in Water and on Land • Organisms adapt to forces present on land or in water • Land: feet and legs to move • Water: fins or webbed feet (duck) • They exert force on both the ground and on water to move and water and earth exert a an equal force in the opposite direction • The Earth has a greater mass allowing objects to move forward • In water the equal and opposite force exerted by the water is called drag force

17. Air • Air, like water is fluid and exerts a drag force on organisms that move through it • Increasing wind speed causes air molecules to move faster, increasing the drag force against a surface area

18. Air- Drag Force • Drag force acts upwards • Drag force is always in a direction opposite to the object’s motion

19. How does Drag Force on Surface area affect flying Animals? • As surface area increases, drag force increases. Drag Force acts in the opposite direction of an object’s fall, thus allowing the objects descent. • Increased surface area decreases the chances of a bird falling to the ground • Wings increase surface area

20. Flight

21. Investigation One Flight

22. What do Forces Cause? • Speeding up • Slowing down • Changing direction

23. Forces in Water and Air • Drag Force oppose motion in a fluid • Air is fluid like water

24. Forces of Gravity • Forces cause objects to accelerate • Force of gravity between an animal and the earth cause animals to accelerate in the direction of the ground • The rate of acceleration is 9.8 m/s² • The force of gravity increases with the mass of the object

25. Forms of Energy • Two forms of energy that an object has as it falls • Gravitation Potential Energy • Possessed by the object due to the fact of being above ground • Higher above the ground the greater potential energy it has • Kinetic Energy • Possessed by the animal due to speed • Faster the animal is falling the greater the kinetic energy • As an object/animal falls the gravitational potential energy decreases and transforms into kinetic energy

26. Drag Force in the Air • A drag force is created by the collision of air molecules with the animal that is flying • Air molecules apply a force that is opposite to the direction of the motion of the animal

27. Drag Force in the Air • Increasing the surface area of the animal increases the drag force • If the drag force produced by all the air molecules is less than the force of gravity the animal will speed up toward the ground, but more slowly than 9.8m/s² • This means the animal will take longer to reach the ground than an animal without drag force

28. Surface Area Influences on Flight Time • Birds and other animals with a larger wing span or surface area, will fall more slowly than animals with a smaller wing span.

29. Mass influencing Flight Time • Without a drag force, mass does not influence the flight time, as all animals accelerate due to gravity 9.8m/s² • With a drag force, the greater the mass the shorter the flight time. • This occurs because for the same drag force a larger force of gravity will cause an object to accelerate faster toward the ground.

30. Investigation Two FLIGHT

31. Drag Force • Drag force acts opposite to the direction of motion • An animal falling towards the ground drag force acts directly upwards • An animal flying horizontally drag force acts horizontally in the opposite direction of motion Drag Force acts horizontally in the opposite direction Animal falling towards the ground Flying Horizontally Drag Force acts upwards

32. Lift Force • Lift force acts perpendicular to the direction of motion • Moving horizontally: lift force acts upwards to keep the object in the air if the lift force equals the force of gravity • If the upward lift force is greater than the force of gravity the bird will speed up in the upward direction and fly upwards • Lift force is less than gravity the bird will speed up toward the ground

33. Lift Force Flying horizontally Lift force acts vertically

34. Lift force • Influenced by surface area • Surface area in the direction of the lift force is the most important • Wing of a bird provides a small surface area in the direction of the lift force to maximize lift force

35. Lift and Drag Force • The faster the bird is moving the greater the drag and lift force • Airplanes must be moving fast enough for a lift force to be greater than the force of gravity

36. Energy Creating lift Force • With a horizontal Speed the bird possess kinetic energy • Kinetic energy can be transformed into potential energy once the bird is above the ground • Sometimes it can be difficult to create enough horizontal speed to generate lift force • Fall from a tree or another object above the ground • Giving them kinetic energy creating lift force

37. Speed of an Animal • To calculate the speed of an animal • measure the distance traveled (m) divided by the time taken (s) • Speed=distance/time • For example: speed= distance/time= 100m/5s = 20m/s

38. Investigation Three Flight

39. Relation between Drag, Lift and Surface Area • Larger surface Area increases drag and lift force • When flying horizontally birds have a small head-on surface area and this minimizes drag force • Birds have a large surface Area that is parallel to the ground this creates a large lift force • Birds can change their orientation to alter lift and drag force

40. Forces that affect Flight • Three Forces that affect Flight • Drag Force • Lift Force • Force of Gravity • In addition to flying through the air some birds develop thrust force- by flapping their wings • Can occur for any object, animal, or bird gliding through the air

41. Thrust Force • According to Newton’s Third Law- air pushes back against the wings with an equal and opposite force that the wings apply to the air • Thrust force on a bird can cause it to speed up in a forward and upward direction • The greater forward speed will also increase the lift force helping the bird to remain in the air

42. Thrust Force- Flapping • Flapping wings requires energy • Chest muscles of a bird produce flapping through chemical potential energy from food • Muscles convert chemical potential energy into kinetic energy • Birds with small wing surface area need to flap their wings more frequently to produce lift and thrust to stay in flight • Birds with larger wing surface area relative to their mass can glide for greater distances requiring less chemical potential energy