EXAM 5 BIOMECHANIC
A .145 kg baseball is traveling at 40m/s. How much work must be done to catch it.
-116 J
WHAT MIGHT AN ATHLETE DO TO MOVE STRAIGHT FORWARD QUICKLY
1,3,4
If a person runs up a flight of 70 steps in 28 seconds. If each step is 20 cm and the person weights 176 lbs. How much mechanical work was done
1120 J
If a lifter snatches 100 kg in 1.5 seconds and the displacement is 2 meters. Approximately, what is the average power of the lift?
1308 W
a perpendicular force of 300N is applied to a door .5 from hinges what is the torque?
150nm
Upon what does the force necessary to overcome the inertia of a projected object depend
168 J
Which of the following levers would be best to use to move a specific object if your only objective was slight movement of the object
2nd class with resistance arm of 10 and force arm of 20
what is the momentum of a 154 ib person running at 5m/s
350 kg m/s
If initial height and landing are the same, the angle of projection that would maximise horizontal displacement is ______ degrees
45
If initial height and landing height are the same, the angle of projection that would maximize horizontal displacement is _____ degrees.
45
if a person has a mass of 80 kg what is their weight ?
784.8 N 176IB
which of the following is newtons 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.
which of the following is the 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 would have the largest vertical force componenet
A force of 600 N applied to a soccer ball at an angle of 70 degrees form the horizontal
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 third-class lever with a resistance arm of 20 and a force arm of 10
Based on the principles of levers, which one of the following levers is most efficient in overcoming a resistance of 20 lbs?
EA = 10 RA = 5
based of the principles of levers which of the following levers is most efficient in overcoming a resistance of 20 ibs
EA = 10' RA = 5''
Which of the following does not describe a way in which machines function?
Enhances force in an attempt to increase total force needed to overcome a resistance
which of the following is true about second class levers
Force arm is always longer, have a mechanical advantage that favors force production
An individual is expecting to be pushed from the left side. What would be the best standing position to assume in order to absorb the force without losing one's balance?
Side stride stance with line of gravity towards left edge of base support
Which of the following statements is false regarding the proportional relationship between force components and resistance components?
The closer the force arm application is to the axis of rotation the greater the amount of resistance that can be moved
Which of the following must be true in order for a state of equilibrium to exist?
The sum of all forces and torques acting on the object must equal zero
Which is true when applying Newton's 3rd law of action/reaction to dribbling a basketball?
action - ball hits floor, reaction - floor pushes ball
Which of the following could be done to reduce the amount of force needed to move a lever?
all of the above
What type of motion is exhibited by the leg segments of a sprinter running a 100 meter dash?
angular
Which of the following statements accurately describes the relationship between linear and angular motion?
angular motion of the joints produces linear motion
which of the following actions increase torque
apply greater force AND apply force at an angle closer to 90 degrees AND lengthen perpendicular distance between axis and point of application of force
The point at which all of the body's mass and weight is equally balanced or equally distributed in all directions is the _____.
center of gravity
what does the center of gravity of an object represent
center of mass of body
which of the following equations for linear acceleration is correct
change in velocity divided by change in time
Force is defined as any influence tending to ________ motion
change/ modify/ cause
what is meant by torque
effective force producing rotary motion at an axis
why is the second class lever well adapted to moving heavy loads
effort arm is longer than resistance arm
which would be the most effective manner in which to lift a heavy box
face box with elbows bent and arms close to body
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
Which pattern of joint motion most clearly typifies push-pull patterns?
flexion/ extension
Mechanical work involves a _________ and a __________ that it moves through
force and distance
which of the following is true about second class levers
force arm ois always stronger, have MA that favors force production
which of the following is not part of kinematics
force producing motion
Kinematics is the description of motion and includes consideration of each of the following except
forces
which of the following makes it difficult for a runner to change either his speed or direction
inertia
which of the following defines the lines of gravity of the body
intersection of cardinal sagittal & frontal planes and vertical lines passing through the center of gravity
which of the following statements is true about kinetic friction
is it the friction between 2 objects that are sliding along each other
Which of the following types of machine is most common in the musculoskeletal system arrangements of the human body
levers
Which of the following types of machines is the most common in the musculoskeletal system arrangements of the human body?
levers
which of the following is the most commin form of simple machine found in teh human body
levers
in which of the following Is torque not found
linear motion
What is the relationship between the angular and linear velocities of a lever?
linear velocity is equal to the angular velocity times the length of the lever
what is the primary factor affecting the stability of an object
location of the center of gravity
The weight of a body is defined as a quantification of the force of gravity acting on which aspect of the body
mass
upon what does the force necessary to overcome the inertia of a projected object depend
mass object and its velocity
Upon what does the force necessary to overcome the inertia of a projected object depend
mass of object and its velocity
what is weight
mass time acceleration due to gravity
Why is it easier for a runner to move his recovery leg forward more rapidly when it is flexed than extended?
movement of inertia if the leg is less when its flexed
which is an example if a linear motion in sports
movement of the center of gravity of a putted golf ball
what is teh international unit to measure force
newton
how much work is done if you hold a tennis racquet in your hand without moving it
none
For two objects in contact with each other which of the following would result in the greatest amount of friction?
one object sitting stationary on the other
What is the true effort arm (moment arm) of a lever in the body?
perpendicular distance from lin eof pull of muscle to axis
what is the true effort arm ( moment arm ) of a lever in the body
perpendicular distance from line of pull of muscle to axis
what determines the type of motion of a freely moveable joint
point at which force is applied
what is inertia?
resistance to change in motion
Which type of motion is produced by any force that is not through the axis of rotation?
rotary
The _________ the time it takes to move a given distance, the greater is the power.
shorter
Why lift a heavy weight by flexing and then extending the knees rather than flexing at the hips and then lifting trunk?
shorter resistance arm
What does a machine with a resistance arm greater than a force arm favor?
speed
Which of the following is not among the general factors that positively affect the achievement of balance?
teh center of gravity falls outside teh base of support
mass is
teh quantity of a matter contained in an object, a measure of inertia, inversely proportional to acceleration
Why is it more difficult to perform a sit-up when the hands are clasped behind the head than when the arms are kept at the side?
the resistance arm is greater
Change in momentum is the result of an impulse. How may the impulse be changed?
time of application of force
Ball A is the same mass as Ball B. If Ball A is hit with twice as much force as Ball B, Ball A's acceleration will be _____ that of Ball B.
twice
Which of the following motions should be avoided in working with long handled implements?
twisting .
which of the following reps a vectoy quantity
velocity of 15 m/s
power equals
work divided by time
which of the following represents a scalar quantity
a mass of 70 kg
which of the following represents a vector quantity
a velocity of 15m/s
which of the following terms is defined as the rate of change in velocity
acceleration
which of the following statements is correct concerning momentum
a 14 ib bowling ball with a linear velocity of 35ft/sec will have greater momentum than an 8ib ball at 50ft/sec
which of the following is teh Law of Acceleration
a change in acceleration of body occurs in the same direction as the force that caused it