CBSE Class 12 Physical Education Kinesiology Biomechanics And Sports Medicine Worksheet

CHAPTER -10

KINESIOLOGY BIOMECHANICS AND SPORTS

Question.  What do you mean by Kinesiology ? 
Answer. KINESIOLOGY means the science of motion without particular reference to mechanics or physics. The term means “Study of movement”. 

Question. What do you mean by Biomechanics? 
Answer– Biomechanics is a sub discipline of physical education. The term ‘biomechanics’ is a combination of two words i.e., ‘Bio’ and ‘mechanics’. Here ‘Bio’ is a Greek word that refers to life or living things and mechanics refers to the field of physics and the forces that act on bodies in motion. 

Question. What is a projectile? 
Answer– An object thrown into the space either horizontally or an acute angle under the action of gravity is called a projectile. There are two forces which act on a projectile – gravitational force and air resistance. 

Question. What is gravity? 
Answer– It is the force of attraction exerted by the earth towards its centre on a body or an object. The greater the weight of an object, the greater the influence of gravity upon it. Gravity affects a projectile as it decreases the height a projectile can obtain. 

Question. What do you mean by air resistance? 
Answer– When projectile moves through the air, it is slowed down by air resistance. Air resistance decrease the horizontal component of a projectile. The effect of air resistance is very small, but it needs to be taken into consideration if you want to increase the horizontal component of a projectile. 

Question. What is linear motion? 
Answer– Linear motion refers to any motion that mones along a straight line in one direction. As a matter of fact, linear motion describes a situation is which movement occurs in a straight line. 

Question. What is angular motion?
Answer– Angular motion is also referred to as rotator motion. It occurs when all points on a body or object move in circular or circular parts of circle about the same fix central line or axis. Angular motion can occur about and axis with the body or outside the body.

Question. Define Work.
Answer– Work refers to an activity involving a force and the movement in the direction of the force. It can also be defined as the work done by a constant force as the product of the force and the distance moved in the direction of the force.

Work = force X Distance

Question. Define power.
Answer– Power is the rate of doing work or the rate of using energy. The above definition can be expressed as an equation.

Power = work/time

Question. Define Energy.
Answer– Energy is the capacity to do work. However, there are various forms of energy but in the field of games and sports our main concern is about mechanical energy. Mechanical energy is the combination of kinetic and potential energy.

Question. What is the difference between linear and angular motion?

Answer– Linear Movement: Linear movement describes a situation in which movement occurs in a straight line. Linear movement can also be called translation but only if parts of the object or the athlete move the same distance, I the same direction, and in the same time frame. As you can imagine, translation rarely occurs in an athlete’s movement because some parts of an athlete’s body can be moving faster than other parts and not always exactly in the same direction. For example: and athlete in the 100 meter sprint wants to prawl the shortest distance from the start to the finish line.

Angular movement: Coaches talk of athletes rotating, spinning, swinging, circling, turning, rolling, pirouetting, somersaulting and twisting. All of these terms indicate that an object or an athlete is turning through an angle, or number of degree. In sports such as gymnastics, basketball, figure skating, diving, handball, jumping the movements used by athletes include quarter turn (90 degrees) half turns (180 degrees) and full turns (360 degrees) slam dunk competitions are great example of basketball players showing off their 360⁰.

Question. What are the factors which affect projectile trajectory?
Answer– 1. Angle of projection: Any object when projected at different angles covers different distance. When it is projected or released at the angle of 30⁰ making a parabolic path, it covers less distance. When it is projected at the angle of 60⁰, it covers a distance less than the distance covered by 30⁰ angle. When it is released at the angle of 45⁰ making a parabolic path it covers the maximum distance. Here it is supposed that the initial velocity in all the case is same.

2. Initial Velocity: The distance covered by an object depends on the initial velocity of the projectile. If the initial velocity is more the object covers maximum distance. On the other hand, if initial velocity is less, the object covers less distance.

3. Gravity: It is the force of attraction exerted by the earth towards its centre on a body or an object. The greater the weight of an object the greater the influence of gravity upon it. Gravity affects a projectile as it decreases the height of projectile can obtain.

Question. What is friction? Explain its types. Is it advantageous or disadvantageous in the field of sports? Give your views.

Answer– The force of friction is the force that depends at the surface of contact of two bodies and opposes their relative motion.

Types

1.   Static friction: The opposing force that comes into play when one body tends to move over the surface of another, but the actual motion has not yet started is called static friction.

2.   Dynamic friction: Dynamic friction is the opposing force that comes into play when one body is actually moving over the surface of another body. Further dynamic friction can be of two types i.e., sliding friction and rolling friction.

Friction is usually called a necessary evil. It means that it is essential in games and sports. Without friction, we cannot give a better performance in the field of sports. For example athletes use spikes and football players use studs to have appropriate friction while they run fast.

On the other hand, friction is disadvantageous in some of the sports and games, such as in cycling, there should not be more friction between road and the tyres of cycle.

Consequently, it can be said that friction is advantageous in some of the sports but in other sports more force of friction is disadvantageous.

Question. Discuss the mechanical analysis of walking in detail.

Answer– Mechanical analysis of walking can be studied in two phases:

1. Stance phase.

2. Swing phase.

1.      Stance Phase: Stance phase is the time when the foot is on the ground. It is considered that it consists of maximum percentage of walking cycle. For a part of the stance phase both feet have a contact with the ground for a period of time. The stance phase of walking can further be divided into the following stages.

(i)     Heel Strike: This stage begins when the heel first touches the ground and continues until the complete foot is on the ground i.e. early flat-foot stage.

(ii)     Early flat-foot: The standing of the early flat-foot stage is that moment when the complete foot is on the ground. The end early flat-foot stage occurs when the body’s centre of gravity (COG) passes over the top of the foot.

(iii)    Late flat-foot:An athlete comes into late flat-foot stage when his body’s CO4 passes in front of the neutral position. This stage lasts when the heel lifts off the ground.

(iv)     Heel rise: This stage starts when the heel begins to leave the ground. The foot functions as a rigid liner to move the body in forward direction.

(v)      Toe off: This begins when the toes leave the ground completely. This stage continues until the beginning of swing phase.

2.      Swing Phase: Swing phase occurs when one foot is on the ground and the other one in the air. The foot which is in the air is called to be in the swing phase. The swing phase in walking is shorter than stance phase.

Question. Discuss the mechanical analysis of ‘running’ in detail.

Answer– The mechanical analysis can be studied properly in the following phase:

1. Stance phase: The stance phase is that phase in which the foot is in contact with the ground. This phase is considered as the more significant of the two phases because during this phase the foot and leg bear the body weight. This phase can be divided into four stages which are described below: 

(i) Initial contact stage: This stage begins at the movement when both feet are off the ground (sometimes referred to as float phase). Suppose the left leg remains in the front and  About to touch the ground. The moment, when the left foot touches the ground (whether touches heel, mid foot or farefoot) is called as initial contact stage.

(ii)   Braking or absorption stage: when the left foot makes the initial contact to the ground in your front, your body starts performing a controlled landing. The left knee and ankle flex and the left foot rolls to absorb forces. It is called braking or absorption stage.

(iii)  Mid stance stage: The braking or absorption stage continues until the left lag is directly under the hip taking maximum load as the body weight passes own it. The ankle and knee are at maximum flexion angle. The entire foot is usually in contact with the ground. The next leg remains in swinging position. It is called mid stance stage.

(iv)  Propulsive stage: Propulsive stage occurs when the supporting leg or left foot leaves the ground and propel your body in forward direction. Propulsion is achieved by your left ankle, knee and hip all extending to push the body up and forward using the elastic energy stored during the absorption phase.

2. Swing phase: Swing phase is initiated with toe off of left foot and ends with initial contact stage with right foot. The swing phase is longer in running in comparison to stance phase.

Question. Define aerodynamics in sports ?

Answer: Aerodynamics is the study of forces and the resulting motion of objects through the air it is related to the flow of air around a projectile, which can influence the speed and direction of the object full stop full stop aerodynamics in sports study of how air resistance and drug effects sports objects and influence performance.

Question. Define flexion and extension ?

Answer:- 1. flexion refers to a movement that decreases the angle between two body parts flexin at the elbow is decreasing the angle between the owner and Di humorous when the knee plexus the angle moves closer to the but ok and the angle between the femur and Tibia gets smaller.

2 .Extension refers to a movement that increase is the angle between two body parts extension at the elbow is increasing the angle between the owner and the humorous extension of the name straightens the lower Limb.

Question. define adduction and abduction Movement in sports?
Answer:-abduction Movement in sports adduction refers to a movement towards the midline to a movement towards the Midnight or Centre, it is a movement of a body part towards the median Plane full stop abduction is a movement away from the midline or Centre, it refers to any movement of the body part away from the median Plane

Question. discuss the muscles involved in running?

Answer:-muscular analysis of sprinting

1. The leg actions in running is one that takes place in a sagittal plane about a frontal axis and involves the hip knee and ankle joints.

2. The bones of the hip involved or dics m oh and pelvic girdle which form a ball and socket joint.

3. The bones of the name involved or December and Tibia which form a Hinge Joint.

4. The bones of the angle in walls are the Tibia and calcareous which form a modified joint.

Question. What do you understand by friction in sports
Answer:- the action of one surface of object having against another it is the resistance resistance that one surface of object in counter when moving over another.

Question. define axis and planes?
Answer:- An axis is a straight line  around which an object rotates. Plane is the surface on which movement take place.

Question. Explain Newton's Law of Motion in sports

Answer:-  Law of inertia:- this law states that a body at rest will remain at rest and a body in motion will remain in motion at the same speed and in the same direction tell any external force is applied on it change that state. application in sports

 Example- In basketball player on the court must keep in mind about Dribbling because the ball will continue to bounce for sometime if they lose control if the ball bouncs to far away from the players his or her team can lose position.

 Newton’s second law of motion-this law states that the acceleration of an object is directly proportional to the force producingits the inversely proportional to its mass

application in sports:-

(i) runners struggle while stopping at the finishing line because it requires a very sudden change in motion

(ii) shot put throw.

Newton’s third law of motion:-

this law states that too every action there is always an equal and opposition reaction

Application in sports:- while swimming, the swimmer pushes the water backwords using his hands thus attains a forward push due to an equal an opposite reaction from the water.