WorksheetsOCT414 Topic 4 - Biomechanic Principles II
Total questions: 55
Worksheet time: 31mins
What is torque?
The tendency of a force to rotate an object
The resistance to motion between two surfaces
The rate of change of velocity
The force that opposes the motion of an object
What is the force arm in a lever system?
The perpendicular distance between the location of force application and the axis of rotation
The distance between the axis and the point of resistance application
The shortest distance from the axis of rotation to the line of action of the force
The greater the distance of the force arm, the more torque produced by the force
What is the mechanical advantage of a wheel and axle?
Radius of wheel / Radius of axle
Radius of axle / Radius of wheel
Force arm / Moment arm
Moment arm / Force arm
What is the purpose of a pulley?
To change the direction of force
To increase the amount of force applied
To decrease the amount of mechanical energy needed
All of the above
What is the law of inertia?
A body in motion tends to remain in motion at the same speed in a straight line unless acted on by a force
A change in acceleration is directly proportional to the force causing it and inversely proportional to the mass of the body
For every action, there is an opposite and equal reaction
The resistance to motion between two surfaces
What is the difference between static friction and kinetic friction?
Static friction occurs between two objects that have not yet begun to move, while kinetic friction occurs between two objects that are sliding upon one another
Static friction is always greater than kinetic friction
Static friction depends on the hardness and roughness of the surface textures
All of the above
What is rolling friction?
Resistance to an object rolling across a surface
Resistance to motion between two surfaces
The rate of change of velocity
The force that opposes the motion of an object
What is the relationship between force and acceleration?
Force is directly proportional to acceleration
Force is inversely proportional to acceleration
Force has no effect on acceleration
Force and acceleration are unrelated
What is the purpose of the law of reaction?
To explain the relationship between force and acceleration
To describe the resistance to motion between two surfaces
To determine the mechanical advantage of a lever system
To explain the equal and opposite reaction to an action force
What is the definition of displacement?
The actual sum length of measurement traveled
The distance that an object moves in a specific amount of time
The resistance to motion between two surfaces
The change in location of a rotating body
What is the relationship between mass and inertia?
The greater the mass, the greater the inertia
The greater the mass, the less the inertia
Mass has no effect on inertia
Mass and inertia are unrelated
What is the purpose of friction in human movement?
To increase speed and acceleration
To decrease speed and acceleration
To provide stability and control
Friction has no effect on human movement
What is the difference between linear motion and angular motion?
Linear motion is motion along a line, while angular motion is rotation around an axis
Linear motion is always faster than angular motion
Linear motion occurs in a straight line, while angular motion occurs in a curved line
Linear motion and angular motion are the same thing
What is the purpose of a compound pulley?
To change the direction of force
To increase the amount of force applied
To decrease the amount of mechanical energy needed
All of the above
What is the relationship between the radius of a wheel and the mechanical advantage of a wheel and axle?
The greater the radius of the wheel, the greater the mechanical advantage
The greater the radius of the wheel, the smaller the mechanical advantage
The radius of the wheel has no effect on the mechanical advantage
The mechanical advantage is equal to the radius of the wheel
Machine that consists of a wheel attached to a central axle about which it revolves
Lever
Pulley
Torque
Wheel and axle
In wheel and axle, forces may be applied to the wheel either at the rim or at the axle
True
False
Basic uses of wheel and axle
Alleviate friction
Increase amount of force (F) applied to rotating body
Increase amount of mechanical energy needed to oppose gravity
Wheel and axle primary use is to
Enhance ROM
Enhance speed of movement
Decrease force needed to a rotating body
Wheels and axles function as a form of lever
True
False
When the wheel turn, the axle remain in the same position
True
False
Mechanical advantage of wheel and axle =
Radius of the wheel divide by radius of the axle
Radius of the axle divide by radius of the wheel
If the wheel radius is greater than the radius of tha axle, the wheel has a mechanical advantage of the axle. Why?
Longer force arm
Longer resistance arm
Wheel and axle: Long bone represents _____, surrounding tissues represent ________
axle, wheel
wheel, axle
Limb rotation about its mechanical axis constitute a movement of the wheel and axle
True
False
In wheel and axle, effort (F) is provided by
Muscles producing the rotation
Antagonistic muscles
External resistance
In wheel and axle, resistance (R) is provided by _____
muscles producing the rotation
antagonistic muscle
external resistance
Wheel and axle: Resistance (R) is applied to the axle (A) from the same distance like the effort (F)
True
False
Wheel and axle: Upper extremity internal rotation
Humerus = Axle
Minimal humerus rotation = Increase ROM of hand and wrist
Minimal humerus rotation = Increase speed
Example of wheel and axle-like arrangements in the body
Badminton: Forearm pronation
Tennis serve: Shoulder internal rotation + elbow bent
What is pulley
Mechanical machine consists of wheel that turns readily on an axle
Machine consists of a wheel attached to a central axle about which it revolves
Types of pulleys (3)
Single-fixed
Single-movable
Combination
Wheel in pulley usually grooved for a rope/wire cable
True
False
- Has a mechanical advantage of TWO
- Has an axle in a movable block
- Supported by two parts of the same rope
Fixed pulley
Movable pulley
Combination pulley
Fixed pulley
Has block and tackle
Has an axle mounted in bearings
Changes direction of the force on a rope that moves along the circumference
Mechanical advantage in fixed pulley can be gained by:
Fixed pulley + Movable pulley
Fixed pulley + Another fixed pulley of a different diameter
Forms block and tackle
Compound pulley can have several pulleys mounted on the fixed and moving axles, further increasing the mechanical advantage
True
False
Anatomical pulleys:
Pulley = Bone, Cartilage, Ligament
Cord = Muscle tendon
Pulley = Muscle tendon
Cord = Bone, Cartilage, Ligament
Single pulleys function to change effective direction of force (F) application
True
False
Each additional rope in pulley increases mechanical advantage by 1
True
False
Single pulley = Mechanical advantage 1
True
False
Examples of pulley system in body
Body patella at knee
Lateral malleolus
Pulley-like arrangements in body patella at knee
Patellar tendon - Patella - Quadriceps arrangement
Quadriceps muscle pull proximally toward their bellies
Pulleys in foot
Peroneus longus = Cord
Lateral malleolus = Pulley
Peroneus longus = Pulley
Lateral malleolus = Cord
TWO types of motion
Linear
Angular
Displacement
Muscular system is source of force in humans
True
False
Which of the following are correct
Linear = Translatory
Angular = Rotary
Linear = Rotary
Angular = Translatory
Rectilinear and curvilinear are part of the translatory motion
True
False
Rectilinear motion
Motion along a straight line
Motion along a curved line
Distance that a system moves in a straight line
Distance that a system moves in a straight line
Rectilinear motion
Curvilinear motion
Linear displacement
Rotary motion
Angular motion of the joints produces the linear motion of walking
True
False
In human body, axis of rotation is provided by the various joints
True
False
Actual sum length of measurement traveled
Distance
Displacement
Velocity
Direction + describes the rate of displacement
How fast an object is moving
Distance that an object moves in a specific amount of time
Change in location of a rotating body
Angular displacement
Linear displacement
Speed
Velocity
