Biomechanics ch. 3 review

Identify Newton's law of acceleration.

A change in the acceleration of a body occurs in the same direction as the force that caused it.

Which of the following terms is defined as the rate of change in velocity?

Acceleration

Which of the following pairs of variables exhibits an inverse relationship?

Both force and the force arm and resistance and the resistance arm

Which of the following does not describe a way in which machines function?

By enhancing force in an attempt to increase total force needed to overcome a resistance

Which of the following statements is true about kinetic friction?

It is the friction between two objects that are sliding along each other.

Which of the following statements is true about velocity?

It is the rate at which an object changes its position.

Which of the following could be done to reduce the amount of force needed to move a lever?

Move the resistance closer to an axis decrease the amount of resistance Apply the force farther from an axis

Which of the following exemplifies a 2nd class lever in the human body?

Plantar flexion of the ankle to raise the body on the toes

Which of the following statements is correct?

Static equilibrium is when the body is at rest or completely motionless.

In the context of the factors in use of anatomical levers, which of the following statements defines the term force arm?

The perpendicular distance between the location of the force application and an axis

Which of the following statements accurately represents the relationship between linear and angular motion?

angular motion of joints produces the linear motion of walking

Which of the following is a type of friction?

both static and kinetic

The __________ is the point at which all of the bodys mass and weight is equally balanced or equally distributed in all directions.

center of gravity

___________ occurs when all the applied and inertial forces acting on a moving body are in balance,resulting in movement with uncharging speed or direction.

dynamic equilibrium

Angular displacement is the change in location of a linearly moving body.

false

Assuming that the bat speed and pitched ball velocity were the same, the ball hit with the middle of the bat would travel farther then the ball hit with the larger end of the bat.

false

In rapid running movements in which moving inertia is high, an individual has to raise the body's center of gravity to maintain balance when stopping or changing direction.

false

In the context of wheels and axles, only the radius of the wheel corresponds to the force arms.

false

Levers rotate about an axis of rotation as a result of force being applied to them to cause their movement in the same direction as the resistance

false

Mass is the effect of gravity on the amount of matter in a body.

false

Slight variations in the location of a force and a resistance have no effect in determining the mechanical advantage (MA) and effective force of a muscle.

false

Velocity is how fast an object is moving, or the distance an object travels in a specific amount of time.

false

in the human body when the triceps applies a force to the olecranon in extending the nonsupported forearm at the elbow, it exemplifies:

first-class levers.

identify newton's law of reaction

for every action there is an opposite and equal reaction

Kinematics is concerned with the description of motion and includes consideration of each of the following except:

force

Which of the following terms refers to the tendency for the current state of motion to be maintained, whether a body segment is moving at a particular velocity or is motionless?

inertia

Which of the following is the most common form of simple machine found in the human body?

levers

Momentum, or the quality of motion, is equal to _____.

mass times velocity

Which of the following is not an example of forces that act individually or in combination to provide mechanical loading that may result in excessive tissue deformation?

straightening

A football player in a four-point stance has more balance than the same football player in a three-point stance.

true

A person riding a bicycle in a straight line at 7.5 miles per hour would be more balanced than the same person riding the bicycle at 4.8 miles per hour in a straight line.

true

Biomechanics is the study of mechanics related to the functional and anatomical analysis of biological systems

true

Dynamics involves the study of systems in motion with acceleration.

true

Friction is the force that results from the resistance between the surfaces of two objects moving on each another.

true

Linear displacement is the distance a system moves in a straight line.

true

Short force arms and long resistance arms require great muscular strength to produce movement.

true

Static friction is always greater than kinetic friction and rolling friction

true

Statics involves the study of systems that are in a constant state of motion

true

The mass of an obj. affects the speed and acceleration of the obj. in physical movements

true

work is equal to

ΔKE + ΔPE + ΔTE force x displacement a change in energy

Which of the following statements is false about forces?

They are relative to the mass of an object.

Which of the following is a primary purpose of wheels and axles in the musculoskeletal system?

To enhance range of motion

Impulse is the product of force and time.

True

In statics all forces acting on a body are in balance, resulting in the body being in equilibrium.

True

In the context of first-class levers, the agonist and antagonist muscle groups may contract simultaneously on either side of a joint axis.

True

Muscles are the main source of force that produces or changes movement of a body segment or an entire body.

True

Which of the following levers would be best to use to move a specific obj. if your only objective was a slight movement of the obj.

a 2nd class lever with a resistance arm of 10 and a force arm of 20

Which of the following levers would be best to use to move a specific object if your only objective was speed of the object's movement?

a 3rd class lever with a resistance arm of 20 and a force arm of 10

Newton's law of inertia states that:

a body in motion tends to remain in motion at the same speed in a straight line unless acted on by a force.