Static force Flashcards
What is the stability of the body pictured above?
STABLE
What is the stability of the body pictured above?
UNSTABLE
The elbow joint belongs to which class of levers?
CLASS 3
What class of lever is demonstrated when a person is standing tip-toe on one foot with the fulcrum at the toe?
CLASS 2
What are levers used for?
*. To lift loads and transfer movement
* are rigid bars free to rotate about their own fixed points known a fulcrum.
* have three classes.
What is a class 2 lever?
Fulcrum at one end, force at the other end, load in between
Give an example of a class 2 lever.
A wheelbarrow
Why do amputees often wear artificial limbs even if they cannot use them?
Restores balance and weight distribution
What is the magnitude of velocity called?
SPEED
What is the scientific notation of the number 53,842,516?
5.3842516 x 10^7
How is the width of the base of support related to stability?
Directly related to stability against toppling force
What happens when you bend the torso in the same direction of an applied force?
It reduces stability
What is the distance traveled when going East 10 km, North 5 km, and West 10 km?
25 km
What is the displacement in the same scenario?
5 km, North
How are weight and mass related?
Directly proportional
What is a push or pull exerted on a body which tends to change the state of motion of the body called?
Force
What is the term for a quantity that represents the amount of matter in a particle or object whose standard unit in the International System (SI) is the kilogram?
Mass
A vector quantity, what is the force exerted on a body by the mass of the Earth which is directly proportional to the mass of that body?
Weight
What is a body said to be in what when the sum of that body’s linear and angular acceleration is equal to zero?
static equilibrium
The natural attraction between physical bodies, especially when one of the bodies is a celestial body, such as the Earth is called what?
Gravity
What is the tendency of a force to produce rotation about an axis called?
Torque
What is acceleration?
Rate of change in velocity with respect to time
A vector quantity, what is the straight-line distance between two points combined with direction called?
Displacement
The fixed point about which a lever may rotate is call a what?
Fulcrum
The rate at which distance with respect to time is traveled in a given direction is a vector quantity called?
Velocity
Where is the center of gravity for someone standing upright?
Approximately 56% of height from soles of feet
The position of the center of mass with respect to the base of support determines what?
Stability
Which is true about the location of the center of gravity of a person?
Changes as the person bends or moves
The tendency of the body to compensate for uneven weight distribution often causes problems for people who have lost an arm, as the continuous compensatory bending of the torso can result in a permanent distortion of what part of the body?
spine
What branch of physics concerns the effect of forces on motion?
Mechanics
Every mass exerts an attractive force on every other mass Is known as
The Law of Gravity
The resistance that one surface or object encounters when moving over another is
friction
The product of force and the distance through which the force acts.
work
What happens when the force parallel to an incline exceeds the frictional force?
The person will slide
How does bending the torso in the opposite direction of an applied force affect stability?
It increases stability
Bending the torso in the same direction of an applied force would
reduce stability
What type of friction is present in the bloodstream under normal conditions?
Viscous
the frictional force dissipates kinetic energy by turning it into
heat
Which is greater: static friction (μs) or kinetic friction (μk)?
Static Friction
The magnitude of the frictional force depends on the nature of the surfaces such that the rougher the surfaces
the greater the frictional force
The magnitude of the frictional force depends not only on the nature of the surfaces, but also on the
force that is perpendicular to the surfaces that presses the surfaces together.
How is force related to an object in motion?
It takes a larger force to get an object moving initially than to keep it in motion
Friction acting on a rolling object versus a sliding object
the same
What is required to do work?
Energy
Referring to the above right triangle what is the value of tanΘ to 3 significant digits?
1.33
A straight line perpendicular to the radius of a circle at one end of an arc and extending from this point to the produced radius which cuts off the arc at its other end is called a
Tangent
What two components serve to reduce friction in joints?
Smooth cartilage and synovial fluid
Without friction, an object that is pushed into motion would continue to move forever. This is in accordance with what?
Newton’s first law
Which of the following statements about friction is true?
Friction is sometimes useful
Which of the following is greatest?
Static Friction
Kinetic Friction
Lubricated friction
Sliding friction
Static Friction
Which of the following statements are true?
Generally, it takes a greater force to get a stationary object moving than to keep an object in motion
To get an object to move along a surface what must be true?
The applied force must exceed the frictional force
Which of the following factors will NOT greatly impact the magnitude of the frictional force?
the size of the contact area between an object and a surface
introduction of a fluid such as oil affects the interface of two surfaces how?
Greatly reduces friction
Which of the following statements is true?
Eliminating all friction would make it much harder to walk
What type of motion is the child experiencing in the image below?
Simple Harmonic Motion
The image above depicts which type of motion?
Translational
What type of motion is depicted in the above image?
Rotation
What type of motion is being experienced by the passengers on this ride?
Translation
The product of force and the distance through which the force acts:
work
Which of the following scenarios result in an increase in resistive force?
increasing the velocity of an object with respect to the air
Passengers on the swings shown above will experience which type of motion?
Rotation
What does T = 1/f represent?
Period
A simple pendulum swinging back and forth from the center position under the force of gravity is an example of this type of motion
simple harmonic motion
What is the kinetic energy formula?
0.5mv^2
The person in the picture above is demonstrating which type of motion?
translational and harmonic motion
Centrifugal forces tend to cause movement
away from a center point
Which force is causing the people seen here, riding the swings, to move away from the center of rotation?
Centrifugal force
The rate of change in velocity with respect to time is known as
Acceleration
For most humans, how does the energy expended at a given walking speed change?
It increases carrying a load on either the head or back
Which of the following is NOT an example of complex motion
A sled going straight down a hill
The center of mass remains at a constant height when
standing erect and stationary
How does the resistive force of air change with motion?
Increases with velocity and surface area n the direction of motion
Which of the following is similar to the simple harmonic motion of a pendulum?
Walking
In which of the following do all parts of the body have the same velocity and acceleration?
Pure translational
In which of the following motion is the rate of change in the angle the same for all parts of the body but the velocity and acceleration along the body depend on the distance from the center?
Pure rotational
What is the relationship between frequency and period?
Inversely proportional
If vf is final velocity and vi is intitial velocity and t is time what is the following formula for?
vf - vi
t
acceleration
To calculate the energy expended per second by a person running, in addition to the person’s speed and their muscle efficiency, what else is needed to know?
leg mass and step length
Which of the following statements are false?
Centripetal force is simply another term for Centrifugal force
Banking the road on a curved track has which of the following effect on the cars driving the track?
increases the speed at which cars may safely travel, making them less likely skid or tip over.
If a body were isolated from all other bodies, it would
have no weight but still have mass.
Which of the following is an example of complex motion?
A bullet fired from a gun
In which situation does resistive force NOT come into play?
A rocket in space
The following symbol Δ, is known as
delta
The symbol used for the spring constant
k
The property of a body that tends to return the body to its original shape after the force is removed is known as
elactisity
The internal force per unit area acting on a material is known as
stress
In 1676 _________ observed that while the body remains elastic, the ratio of stress to strain is constant.
Robert Hooke
The fractional change in length Δl / l is called the
longitudinal strain.
A short duration force may also be referred to as
Impulsive Force.
After the age of 65, about 60 % of men and about 75 % of women are affected by this joint disease characterized by a degenerative wearing out of the components of the joint such as the synovial membrane and cartilage tissue
Osteoarthritis
Young’s Modulus is defined as
the ratio of the tensile stress to the tensile strain
The force that holds a material together
Cohesive Force
In which of the following is collision time shortened?
When a person falls into snow
When a person falls into sand
When a car hits a tree
When a person dives into water
When a car hits a tree
In a collision, when is a body’s momentum zero?
after the impact when the body is at rest,
Ideally, in a collision what device should deflate immediately after impact?
when deployed, airbags in vehicles
Which of the following is true regarding the impusive forces after a collision?
impulsive forces take place over a short duration
Over what distance that the decelerating impact force acts over is it possible for a person who jumps out of an airplane to survive a failed parachute?
over approximately 1 meter
When the cohesive force exceeds the applied force, what happens?
the material compresses
The well-known whiplash injury is due to the muscles in the _____ not responding fast enough, causing all of the energy from a sudden impact such as a rear-end collision to be absorbed by ________________________________.
neck, the neck bones (cervical spine)
the formula for stress S is
S = F/A
The capital letter delta, Δ, is used to denote what?
Change
The symbol, ≡, means what?
is defined as
Which of the following statements are false?
When walking or running, center of mass varies in height (H).
When walking or running, center of mass remains at a constant height (H).
When standing erect and stationary, the center of mass is at approximately 56% of the height measured from the soles of the feet.
The center of mass plays an important role in stability
When walking or running, center of mass remains at a constant height (H).
Which of the following quantities is a vector?
Weight
Speed
Distance
Mass
Weight
Which of the following factors is a scaler?
Weight
Velocity
Distance
Displacement
Distance
The symbol for height is
h
How is collision time Affected?
If both objects are hard the collision time will be short
Deceleration always refers to acceleration in what direction?
the direction opposite to the direction of the velocity
Which of the following statements is true regarding the property of elasticity?
the property of a body that tends to return the body to its original shape after the force is removed
Elasticity has no limit
the original shpe is always restored no matter the size of the applied force
Elasticity is very fragile and almost alway results in rupture of the body no matter how minute the applied force is
the property of a body that tends to return the body to its original shape after the force is removed
What states that a body partially or wholly submerged in a fluid is buoyed upward by a force that is equal in magnitude to the weight of the displaced fluid?
Archimedes’ Principle
A measure of a fluid’s resistance to flow and deformation by stress due to internal friction
Viscosity
What is laminar flow?
Type of fluid flow that travels smoothly
Identify the flow profile pictured BELOW
Laminar Flow
A type of fluid flow in which the fluid undergoes irregular fluctuations, or mixing
Turbulence
The single best predictor of the type of flow; the ratio of inertial force to viscous force
Reynold’s number
A blood vessel that carries blood back to the heart
vein
A vessel that carries blood away from the heart
Artery
An abnormal narrowing or stricture of a passage or vessel
Stenosis
The maximum pressure driving the blood at the peak of the pulse
Systolic Pressure
The minimum arterial pressure during relaxation and dilatation of the ventricles of the heart when the ventricles are receiving or fill with blood
Diastolic Pressure
A substance that continually and smoothly deforms when shear stress is applied to it. It includes liquid, gas and plasma is called
fluid
Tension that prevents the molecules of a liquid from separating at the surface; created by the attractive cohesion forces between the molecules of the liquid
Surface tension
One newton per meter squared
pascal
A measure of the amount of space that a substance or an object takes up
Volume
___________________ gives the relationship between velocity, pressure and elevation in a line of flow.
Bernoulli’s Equation
Why is pressure greater in a fluid the deeper you go?
Due to the weight of the fluid above
What are the two upper chambers of the heart from which blood is passed to the ventricles called?
Atria
What are the two lower chambers of the heart; the main pumping chambers?
Ventricles
What is a Bruit?
An abnormal sound heard on auscultation of a vessel, generated by turbulent flow
What principle states that in an incompressible liquid, the increase in pressure at any point is transmitted undiminished to all other points?
Pascal’s principle
What is the attractive force called when a liquid is contained in a vessel and the surface molecules near the wall are attracted to the wall?
Adhesion
The attractive force exerted by a liquid that pulls the molecules in the opposite direction of the container walls
cohesion
Which of the following statements is FALSE about surfactants?
Surfactants are molecules that lower surface tension
Surfactants have a hydrophobic molecule at one end and a hydrophilic molecule at the other end
The word surfactant is an abbreviation of surface-active agent
Surfactants make soluble substances more insoluble
Surfactants make soluble substances more insoluble
What is the buildup of fats, cholesterol, and other substances in and on your artery walls called?
Plaque
What is the correct order for the cardiac circulatory pathway?
Vena Cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta
The differences in the physical properties of solids, liquids, and gases are explained in terms of all the following EXCEPT?
The differences in the physical properties of solids, liquids, and gases are explained in terms of all of the following EXCEPT
the forces that bind the molecules
how its shape is defined
how its volume is defined
the fact that they all transmit force the same
The fact that they all transmit force the same
Pressure can be measured in all the units below EXCEPT?
Pascals
Torrs
Atmospheres
Ohms
Ohms
In the image below which vessel shows the greatest stenosis?
C
