Dynamics and muscle contraction

Question 1

What does dynamics study?

Answer 1

The relationship between the motion of bodies and the causes (forces) that generate it

Question 2

What is newtons first law?

Answer 2

That if a body is at rest or at moving at a constant speed in a straight line it will remain at rest or keep moving in a straight line at a constant speed unless acted upon

Question 3

2 different name for Newtons first law

Answer 3

1st principle of dynamics
Principle of inertia

Question 4

What is newtons second law?

Answer 4

The acceleration of an object is dependent on 2 variables:
The net force acting upon the object
The mass of the object

Question 5

How are F and a proportional?

Answer 5

Directly

Question 6

How are m and a proportional?

Answer 6

Inversely

Question 7

What is center of mass (COM)?

Answer 7

The point in a system that responds to external forces as if the total mass of the system were concentrated at this point
Mean position of the mass in an object

Question 8

What is the center of gravity (COG)?

Answer 8

The point where the mass of the body is concentrated

Question 9

When are COM and COG the same?

Answer 9

When the gravitational field is uniform across an object

Question 10

What 3 things can forces do?

Answer 10

Impart an acceleration to a body free to move
Deform a constrained body
Rotate a body around a point (torque) if force is applied to a point of rotation

Question 11

What does the centripetal force cause?

Answer 11

The tendency to move towards the centre

Question 12

What does the centrifugal force cause?

Answer 12

The tendency to move straight without turning

Question 13

What force do we feel when a car is turning?

Answer 13

The centrifugal force

Question 14

What kind of force is centrifugal force?

Answer 14

An apparent force, it is not real

Question 15

What kind of proportionality is there between the deformation and force applied?

Answer 15

Linear

Question 16

2 ways to measure forces

Answer 16

Statically or dynamically

Question 17

What kind of quantity is force?

Answer 17

Derived

Question 18

What is the difference between the Kg weight and the mass?

Answer 18

Mass is constant, Kg weight depends on force

Question 19

What is the relative density?

Answer 19

The ratio between the mass of a certain volume of a substance and the mass of an equal volume of distilled water at 4c*

Question 20

What is the absolute density?

Answer 20

Ratio between the mass of a body and its volume

Question 21

What is the relative specific weight?

Answer 21

Ratio of weight of a body and weight of an equal volume of distilled water at 4c*

Question 22

What is the absolute specific weight?

Answer 22

Ratio between weight of a body and its volume

Question 23

What is the torque?

Answer 23

The vectorial product of 2 vectors

Question 24

What is Newton’s third law?

Answer 24

For every action force in nature there is an opposite and equal reaction

Question 25

What symbol defines momentum?

Answer 25

q

Question 26

Equation of momentum

Answer 26

q=m • v

Question 27

What is the electrostatic force defined by?

Answer 27

Coloumbs law

Question 28

What is the columb derived from?

Answer 28

Ampere

Question 29

What are the 2 properties of matter?

Answer 29

Charge Mass

Question 30

Formula for centripetal acceleration

Answer 30

v^2/r

Question 31

What is restoring force in SHM?

Answer 31

Force that brings the body back to the center of oscillation

Question 32

What composition does fast animals tend to have?

Answer 32

Long, light limbs and powerful muscles

Question 33

How do you change m/s into km/h?

Answer 33

Multiply by 3.6

Question 34

What is the speed of the animal directly proportional to?

Answer 34

Muscle strength The extent of the contraction

Question 35

What do muscles convert chemical energy into?

Answer 35

Mechanical work

Question 36

What is the efficiency of muscle always?

Answer 36

Less than 100%

Question 37

2 types of muscle contraction

Answer 37

Isotonic Isometric

Question 38

What is isotonic muscle contraction?

Answer 38

When muscle is performing work against an external force (shortens or stretches)

Question 39

What is isometric muscle contraction?

Answer 39

When muscle contracts to balance and external force but neither lengthens or shortens

Question 40

What happens during isometric contraction?

Answer 40

Muscle doesn't shorten Sarcomeres shorten (generating force) Elastic elements stretch, allowing length of muscle not to vary

Question 41

What happens during isotonic contraction?

Answer 41

Sarcomeres shorten more Elastic elements are already stretched so entire muscle shortens

Question 42

When is the tension force (T) maximum during isometric contraction?

Answer 42

When length (L) of muscle is equal to that at rest (L0)

Question 43

What happens when the muscle is shorter or more stretched during isometric contraction than in the resting position?

Answer 43

It developed less strength

Question 44

At resting length, is the passive tension of a muscle 0?

Answer 44

No

Question 45

What happens if we cut the tendon of the muscle at resting tension?

Answer 45

It would get 20% shorter

Question 46

What does the shortening change in length (^L) depend on in isotonic contraction?

Answer 46

The load

Question 47

When is the shortening ^L in isotonic contraction equal to 0?

Answer 47

When maximum force (tension), Max is equal to the external load (F) Tmax=Fmax

Question 48

When is the shortening ^L in isotonic contraction its maximum?

Answer 48

When the load is 0

Question 49

What kind of graph does the defence of the shortening on the load make?

Answer 49

A linear graph

Question 50

What is the external load (F) equal to during isotonic contraction when the work and power produced are maximum?

Answer 50

F=1/2*Fmax

Question 51

What is the absorbed power of muscles

Answer 51

Energy consumed in the unit of time

Question 52

What is the power produced in muscles?

Answer 52

Useful work in the unit time

Question 53

How many joules is 1 calorie?

Answer 53

1 cal = 4.184 J