BIOMECHANICS FINALS

Created by:

montedugas  on May 7, 2012

Pop out
No Messages

BIOMECHANICS FINALS

 T/F: Calculating the range of motion at the hip joint during stair ascent after visually observing the movement is quantitative analysisTRUE
1/200
Preview our new flashcards mode!

Order by

Definitions

T/F: Calculating the range of motion at the hip joint during stair ascent after visually observing the movement is quantitative analysis TRUE
T/F:The motion of a parachutist in the air is an example of translational motion TRUE
T/F:The x- and- y axis in a two dimensional rectangular reference system are always oriented vertically and horizontally, respectively FALSE
With coordination reference system originating at the hip joint, the axes of the coordinate system will always be horizontal and vertical FALSE
T/F: A 3D reference frame has three axes TRUE
T/F:Speed is a scalar quantity TRUE
T/F:Acceleration is defined as the time rate of change of position FALSE
T/F: Displacement is a scalar quantity FALSE
T/F: The slope of a line tangent to a curve indicates instantaneous velocity TRUE
T/F:Vectors can be added together graphically by placing the head of one vector at the tail of the other vector TRUE
T/F: The area under a displacement-time graph represents the average velocity FALSE
T/F: Positive acceleration always relates to the direction of motion away from the origin FALSE
T/F: The point where the velocity is maximum in a velocity-time graph indicates the point where accelerates is maximum FALSE
T/F: Velocity is a measure of the area under the position-time curve FALSE
T/F: The steepness of the slope of a velocity-time-curve is an indication of the magnitude of acceleration TRUE
T/F: Stride length is measured from the hell contact of one foot to the hell contact of the other foot FALSE
T/F:The support phase in walking accounts for the same percentage of the total cycle as running FALSE
T/F: Walking speed is increased by first increasing stride length and the stride rate FALSE
T/F:Successful sprinters can usually increase their acceleration at the end of the race FALSE
T/F: During running, stride length can affect metabolic cost TRUE
T/F: In a gold swing, the club head should be decelerating past contact with the ball TRUE
T/F:Maximum acceleration of the club head occurs at the moment of impact in a golf swing FALSE
T/F: Velocity of wheelchair propulsion is increased by increasing the length of the push on the wheel FALSE
T/F: Horizontal motion of a projectile is a special case of constant acceleration and determines, among other factors, the range of the projectile TRUE
T/F: Vertical velocity of a projectile is affected by gravity TRUE
T/F: Projectiles are never affected by air resistance FALSE
Convert the rectangular coordinates of (122, 10) to polar coordinates(122.4, 4.69)
Convert the polar coordinates of (135, 182) to rectangular coordinates(-134.9, -4.71)
Figure 8-11 depicts the path of a runner. If the runner starts and end at the end of each block, and if each block is square with lengths of 200 meters, what is the magnitude of the resultant displacement of the runner? 894
A swimmer completes six laps in a 50-m swimming pool, finishing where he started. What were the linear distance and the linear displacement? Distance= 300; displacement= 0
A basketball player shoots from beyond the 3 point arc. The ball leaves the hand of an initial velocity of 8 m/s angled 52 degrees from the horizontal. What are the horizontal and vertical velocities of the basketball? Vx= 4.9 m/s
Vy= 6.3 m/s
At takeoff, the horizontal and vertical velocities of a long jumper are 7.6 m/s and 3 m/s, respectively. What are the resultant velocity and angle takeoff? V= 8.17 m/s
angle= 2.15 deg
Given a right triangle with hypotenuse= 12.5cm, side y= 7.2 cm, find the length of side X and the size of the other two angle Size X= 10.2 cm
angle 1= 32.5 deg
angle 2= 54.8 deg
Suppose an individual moves from point s1 (6,9) to point s2 (11,10) to point s3 (5,6). What are the horizontal, vertical, and resultant displacement? -Horizontal= 1 units
-Vertical= 3 units
- Resultant= 3.16 units
Combine the following two vectors to find the resultant vector. Vector A= 7.4 units at 30 deg and vector B= 11.1 units at 120 deg Resultant = 13.34 unites
angle= 86.3
An individual drives 50 km in 72 minutes. What was the average speed in meters per second? 11.57
A train accelerates from rest at a constant acceleration of 10 m/s2? How fast is it going after 5s? 50 m/s
The initial velocity of a projectile is 45 m/s at 72 deg. How high above the ground and how far horizontally is the object when it is 4.7 s into flight? Vertical= 92.78m
Horizontal= 65.38m
A triple jumper needs a velocity of 9 m/s to make a good jump. If he is accelerating at 1.7 m/s2, how much time does he need to reach the velocity 5.29 s
A vaulter is trying to reach a velocity of 8 m/s at the end of a 15-m runway. How quickly must she accelerate? 2.13 m/s2
A sprinter starts from rest and reaches a maximum velocity of 7.4 m/s in 2.5s. What was the average acceleration from rest to maximum velocity? 2.96 m/s2
A higher jumper takes off with a vertical velocity of 4.2 m/s. How long does it take the jumper to reach the peak height of the jump? 0.43 s
Gold ball A is driven straight out from a tee box that is 2 m above the fairway. At the instant the club contacts the ball, another golfer drops ball B from a height of 2 m. Which ball will contact the ground first? Both balls will make the contact at the same time
Questions 18-24: A baseball is thrown with a velocity of 31 m/s at an angle of 40 degrees from a height of 1.8m Vx= 23.75 m/s
Vy= 19.93 m/s
Calculate the time peak trajectory 2.03 s
Calculate the height of the trajectory from the point of release 20.21 m
Calculate the total height of the parabola 22.03 m
Calculate the time from apex to the ground 2.12 s
Calculate the total flight time 4.15 s
Calculate the range of the throw 98.6 m
A baseball leaving the bat at 46 deg at a height of 1.2 m from the ground clears a 3m high wall 125 meters from home plate. What is the initial velocity of the ball (ignoring air resistance) 35.26 m/s
T/F: A thigh segment with an angular velocity of -3.2 radians/s is extending TRUE
T/F:Choking up on a bat in baseball is done to increase the angular velocity of the bat FALSE
T/F:With increased speed of running, there is a concomitant increase in the amount of plantarflexion at heel strike FALSE
T/F:Angular acceleration of the gold club is at the maximum level when the left arm's angular acceleration is zero TRUE
T/F: All points on a thigh flexing through 75 degrees undergo a similar amount of rotation TRUE
T/F:Linear acceleration toward the axis of rotation in a rotating lever is termed centripetal acceleration TRUE
T/F: The relative angle between the trunk and the arm abducted out to the side is 90 degrees TRUE
T/F:Trunk extension accompanies shoulder flexion and elbow extension in wheelchair propulsion FALSE
T/F:The absolute angle of the thigh when standing upright is 0 deg FALSE
T/F:Walking uphill results in an increase in range motion at the hip, knee, and ankle joints, and walking downhill results in a decrease in range motion TRUE
T/F: A radian is an angle formed when the length of the radius is equal to the length of the arc TRUE
T/F: There is minimal motion at the wrist joint during the wheel-chair propulsions FALSE
T/F: Linear displacement of a point on a lever is a function of the length of the radius and the angular velocity FALSE
T/F: A vertex is the angle between two segments FALSE
T/F:Positive angular velocity indicates that counterclockwise movement is occurring FALSE
T/F:Maximum rearfoot angle occurs at heel strike in running FALSE
T/F: The law of cosines provides the tool for computing relative angles between two segments not at a right angle to each other TRUE
T/F: In human locomotion, the knee joint angle is always in flexion at contact in the support phase TRUE
T/F:Angle-angle diagrams usually plot a relative angel against an absolute angle TRUE
T/F: Absolute angles are always computed with respect to the right horizontal FALSE
T/F: Most movements in running occur in the frontal plane FALSE
T/F: The swing plane for golf is upright FALSE
T/F: The initiation of the downswing in golf occurs with the change in angle of the wrists FALSE
T/F: The most used angular unit in biomechanics is the radian TRUE
T/F:Average angular velocity is the slope of secant to an angle-time curve TRUE
Questions 1-4: A golf club 1.01m long completes a downswing in 0.25s through a range of 180 deg. Assume a uniform angular velocity...
1. What is the average angular velocity of the club? 12.57 rad/s
2. What is the linear distance moved by the end of the club? 3.17 m
3. What is the tangential velocity of the end of the club? 12.70 m/s
4. What is the tangential acceleration of the end of the club? 0 m/s2
During an elbow flexion exercise, the relative angle at the elbow is 22 deg at .3s and 155 deg 0.62s. What is the angular velocity of the elbow? 415.6 deg/sec
If the angular velocity at 0.19s is 3.2 rads and 1.2 rads/s at 0.27s, what is the average angular acceleration over this time interval? -25 rad/s2
If a skater is rotating during a spin at a constant angular velocity of 2.5 rad/s for 1.1 s what is the angular acceleration? 0 rad/s2
An object is spinning at 4 rev/s and starts decelerating 0.9 rev/s2. How long will it take the object to stop? 4.44s
The kicking phase of a soccer kick takes place over 0.096s and includes hip flexion (23 deg) and knee extension (29 deg). If the thigh is 0.61 m long and the leg 0.51 m long, what is the tangential velocity of the foot resulting from these movements? 5.24 m/s
If a discus thrower rotates through the last 45 deg of a turn 0.11 s and the distance from the axis of rotation to the center of the discuss is 1.22 m, calculate the average linear velocity of the discus 8.71 m/s
An object is spinning at a constant angular velocity of 13.9 rad/s. If it spins for 1.9s. what is the angular distance traveled? 26.42 rad
A hammer thrower releases the hammer after reaching an angular velocity of 14.9 rad/s. If the hammer is 1.6m from the shoulder joint, what is the linear velocity at release? 23.84 m/s
Calculate the relative angle at the knee and the absolute angles of the leg in degree given the following positions: hip (2.128, 1.891), knee (2.122, 1.642), ankle (1.897, 1.210) Abs= 62.48 deg; rel= 26.14 deg
(Look at paper for chart) chapt 9-#14
Calculate the angular acceleration at fram 40
20.33 r/s2
An ice skater rotating around a vertical axis increases in angular velocity from 450 deg/s to 610 deg/s in 2.3 seconds. Find the angular acceleration 0.12 deg/s2
A baseball bat is swung through a 140 deg in 0.7s. What is the angular acceleration? (assuming zero initial velocity) 571.4 deg/s2
Angular velocity of a rotating object changes from 650 deg/s to 495 deg/s in 1.2 seconds. What is the angular acceleration? -129.17 deg/s2
A cyclist completes 3.2 cycle revolutions in 1.4 s. What is the angular velocity in radians per second? 14.36
An individual's arm segment is 0.18 m long and has an angular velocity of 117 deg/s. What is the tangential velocity of the wrist? 0.37 m/s
A diver accelerates through a somersault at 950 deg/s from standing. What is the angular displacement over 0.15s? 10.69 deg
An individual is running around with a 11-m radius at 3.75 m/s. What is the runner's centripetal acceleration 1.28 m/s2
The final angular velocity of a gold swing was 370 deg/s with a constant angular acceleration of 580 deg/s2. How far did the club rotate? 118 deg
If the linear velocity of a club head in the golf swing is 50 m/s at impact, what was the angular velocity if the club is 0.95 m long? 52.6 rad/s
A baseball bat is rotating at 350 rpm at contact. What is the angular velocity in radians per second? 36.6
In the release phase of bowling, the bowler's arm and forearm travel through 0.23 and 0.27 radians, respectively, in 0.03 seconds. If the length of the arm is 0.8 m and the forearm 0.5 m, what is the tangential velocity of the ball results from these two movement? 10.64 m/s
T/F: Body weight is a measure of intertia FALSE
T/F:Muscle forces are always applied via either a pull or a push FALSE
T/F:When a force vector is resolved into horizontal and vertical components, the orthogonal components are always greater than the magnitude of the resultant vector FALSE
T/F:Gravitational force is the same no matter where in the world a person is TRUE
T/F:The force applied to a javelin by air resistance can both assist and retard its flight TRUE
T/F:The anteroposterior GRF in walking is much greater than the mediolateral GRP TRUE
T/F:An object cannot move unless a force is applied to it FALSE
T/F:The rate at which work is performed is termed potential energy FALSE
T/F: Force is scaler quantity FALSE
T/F:Concurrent forces acting in the sample plane can be combined using composition FALSE
T/F:A spinning ball curves in the direction of the spin because of the Magnus effect TRUE
T/F:An efficient force application to the rim in wheelchair propulsion is not always directed tangentially along the rim TRUE
T/F:Impulse can be measured directly by calculating the area under a force-time-curve TRUE
T/F:All segmental movements in the body occur as a result of a contact force generated by muscles FALSE
T/F:An object with a mass of 100 kg cannot be lifted unless the upward force applied is greater than 981N TRUE
T/F: Two individuals are being measured on the force platform as they perform vertical jumps. The lighter of the two individuals always generates a lower vertical impulse value FALSE
T/F:The anteroposterior GRF for a runner moving at a constant pace is constant FALSE
T/F:A heavier person has an easier time walking across an icy pond because of higher friction TRUE
T/F:Laminar flow usually occurs only at high velocities FALSE
T/F: The greater the area, the greater the pressure FALSE
T/F: Center of pressure is a displacement measure FALSE
T/F: A long jumper in flight has only kinetic energy and no strain or potential energy FALSE
T/F: Successful golfers maximize the acceleration of the club in the initial stages of the downswing FALSE
T/F: In static analysis, the sum of all the forces acting on the body equals zero TRUE
T/F: Mechanical work can be computed by measuring the change in mechanical energy TRUE
What are the horizontal and vertical components of a force with a magnitude of 72N acting at 16 deg to the horizontal? Fy= 19.85 N
Fx= 69.21 N
The horizontal and vertical components of a force are 35.52N and 12.23 N, respectively. What is the magnitude of the resultant vector? 34.74N
How much force must be exerted to accelerate a 240-N weight to 5.7 m/s2 139.45N
What is the coefficient of friction if the friction force is 77.4 N the normal force is 120 N? 0.65
If an individual's thigh exerts a force of 9.1 N at a velocity of 1.4 m/s, what is the power generated by the thigh? 12.74 W
If the static coefficient of friction of a basketball shoe on a particular playing surface is 0.51 and the normal force is 820N, what horizontal force is necessary to cause the shoe to slide? 418.2 N
An individual lifts a 95kg weight to a height of 2.13 m. When the weight is held overhead, what is the potential energy (relative to the floor)? What is the kinetic energy? PE= 1985.1 J
KE= 0.0 J
Calculate the impulse of the graph on the right (look at cht 10 #8) 44.0 Ns
Consider the following free body diagram. Using static analysis, solve for horizontal and vertical forces and C that will maintain this system in equilibrium if A= 110N, B= 85N, and W=45N
(CHT 10 #9)
Fy= 50.1 N
Fx= 155.4 N
Calculate the height of the cneter of mass above its starting height during a squat jump based on the following information: BW 670 N, average vertical force= 788 N, and time of force application- 0.9s 0.12 m
Calculate the height of the center of mass above its starting height during a jump on the hypothetical graph on the right (jumper's weight = 700 N)
(CHT 10 #11)
1.03 m
An object accelerates at 4.7 m/s2 after a force of 810 N is applied. What is the mass of the object? 172.34 kg
An object weighing 1100 N accelerates upward at a rate of 4.1 m/s2. How much force was applied? 1559.73N
A 7000-kg truck starts to roll down a road with a 30 deg incline. People rush to stop it. How much force must they apply to stop it? 34335 N
A 111 kg football payer is running toward you at 12 m/s. What impulse will you have to generate to stop him? 1332 N
A basketball player massing 105 kg applied a vertical force of 2980 N against the ground for 0.11 s. How high did his center of mass rise during his rebound? 0.21m
What is the momentum of a 70 kg runner sprinting at 6.3 m/s? 441 kgm/s
A women with a mass of 60 kg dives from a 10 m platform. What is her potential and kinetic energy when she is 7m above the water? Assuming potential energy is zero at the surface of the water. KE= 1766 J
PE= 4120 J
A 75-kg high jumper raises his center of mass 2.5 m while he clearing the bar. What is his potential energy and kinetic reference to the ground? PEO= 1839.38 J
KEO=0 J
A constant force of 160 N acts on a body in the horizontal direction. The force moves the object forward 75 m in 2.3s startling from resulting with constant acceleration. What is the mass of the body? 5.64 kg
A 15,000 truck is traveling at 25 m/s/. What would be the velocity of a 6500 kg truck with the same momentum? 57.69 kgm/s
A running back is tackled with a force of 3800 N by a linebacker weighing 1000 N. What was the acceleration of the linebacker? 37.3 m/s2
What is the pressure on the bottom of the foot making contact over an area of approximately 100 cm2? 7.36 N/cm2
The work calculated at time 1 and time 2 was 178 N and 345 Nm, respectively. Calculate the power if the time interval was 0.049s 3408.2W
How much power is generated in the horizontal direction by a force of 850 N applied to an object at an angle of 25 deg, causing the object to move horizontally 4m in 1.6s with a constant velocity? 1925.9 W
T/F: A torque that causes rotation action through the pivot point FALSE
T/F: By convention, counterclockwise torques are considered to be poIstive TRUE
T/F: A third-class lever is favorable for force production FALSE
T/F: A first- class lever always favors range of motion FALSE
T/F:Reducing the moment of inertia about an axis through the shoulder joint requires more muscle force to move the limb FALSE
T/F: A skater who is spinning can reduce the angular momentum by extending the arms and legs FALSE
T/F: The moment arm for muscle force changes throughout the range of motion TRUE
T/F: A ground reaction force applied in front of the cneter of mass creates a clockwise turning effect, assuming the person is facing to the right FALSE
T/F: A negative net moment can indicate an eccentric muscle action FALSE
T/F: The sum of torques about the center of mass of an object always equals zero FALSE
T/F: The mechanical advantage of a second-class lever is always less than 1 FALSE
T/F: Remote angular momentum is the angular momentum of a segment about another segment's center of mass FALSE
T/F: The only torque acting on an arm held out to the side is the torque generated by the muscle force FASE
T/F:Angular power is the product of net moment and the joint angular velocity TRUE
T/F: The moment arm is always measured from the pint of application of the force to the axis of rotation FALSE
T/F: A higher center of gravity in a gold club can result in desirable flight paths FALSE
T/F: A force couple produces rotation and translation FALSE
T/F:Total body angular momentum can be increased during a dive by forcefully swinging arms downward FALSE
T/F: The moment of inertia about an axis though the center of mass is less than the moment of inertia about another parallel axis running through any other point on the segment TRUE
T/F: The final acceleration in the gold club during the downswing is attributed to the wrists uncocking FALSE
T/F: Using action-reaction in the air, the legs can be brought up by swinging up the arms TRUE
T/F: The angular acceleration of a rotating body is not influenced by its moment of inertia FALSE
T/F: During the stance phase of running, positive power is produced at the hip, knee, and ankle joint TRUE
T/F: The shoulder joint torques contribute more power in wheelchair propulsion than the elbow joint torques TRUE
T/F: The moment of inertia about the center of mass for longitudinal and the transverse axes are equal FALSE
A force of 213 N is exerted 0.25 m from the axis of rotation. What is the resulting moment of force? 53.25 N-m
An object has a moment of inertia of 150 kg-m2. A torque of 72 N-m is applied to the object. What is the angular acceleration? 0.48 rad/s2
A 70-kg gymnast, facing to the right, applies a vertical ground reaction force of 1300 N at 0.2 m behind the center of mass. What is the torque generated about the center of mass? -260 N-m
If a force of 120 N acting 0.29 m from the axis of rotation is balanced by another force of 92 N, what is the moment arm of the second force? 0.38 m
What is the torque generated at the elbow by a 90-N force pulling on the forearm at an angle of 110 deg from the horizon at a point 18 cm from the elbow's axis of rotation . The forearm is positioned horizontal to the ground 15.22 N-m
How much torque must be generated by the deltoid muscle to hold a 60-N dumbbell straight out, to the right, at 1 90 deg arm position? The dumbbell is 0.6 m from the shoulder joint. The center of mass of the arm, weighing 30 N, is 0.25 m from the shoulder joint. The moment arm of the deltoid muscle is 0.05 m 43.5 N-m
Calculate the rotational energy of a segment, given mass of the segment 4.59 kg, moment of inertia 0.057 kg-m2, and angular velocity 1.90 rad/s 0.010 J
A force of 200 N is applied at a point 1.3 m from the axis of rotation, causing a revolving door to accelerate at 6.2 rad/s2. What is the moment of inertia of the door from its axis of rotation? 41.94 kg-m2
If the net moment at a joint is 25.15 N-m and the angular velocity at the same instant in time is 1.64 rad/s, what is the angular power at that joint? 41.25 W
The center of mass of the following three point system with masses 8, 5.4, and 9 kg at the coordinates (4,7), (9.2, 5.6), and (7,4), respectively, is ______ 6.46, and 5.46
What is the angular momentum if a force of 54 N, what a lever arm of 3.4 m, has been applied for 2.7 s from resting? 496 kgm2/s
What are the coordinates of the center of mass of a segment with the proximal end (5.7, 3.2) and the distal end (7.9, 4.1) if the center of mass is 48.6% from the proximal end of the segment? 6.77, 3.64
Calculate the moment of inertia of a baseball bat about its proximal end if its mass is 2 kg and has a radius of gyration of 0.55 and a length of 0.864m 0.452 kgm2
A torque of 68 Nm results in a rotation through 0.57 rad in 0.3 s. How much angular work was done? 38.8 J
Consider the following free body diagram. Using static analysis, solve for the muscle torque that will place this system in equilibrium given mass of the leg and foot 5.3 kg, distance from the knee joint to the center of mass of leg-foot system- 0.152 m; weight of the barbell 150 N, and distance from the knee joint to the center of mass of the barbell 0.521 m
(cht 11 # 16)
86.05 Nm
If the leg is at an angle of 15 deg below the horizontal, calculate the moment arm of the torque caused by the weight of the leg, given that distance to the center of mass of the leg 0.17 m 0.16 m
An object has a moment of inertia of 164 kgm2. A torque of 89.3 Nm is applied to the object in 5s. What is the angular acceleration? 2.72 rad/s2
Consider the following diagram of the biceps brachii acting on the radius in two joint positions. The angle of pull of the biceps brachii force changes from 15 deg to 30 deg. If the muscle force is 900 N and the attachment site of the muscle is 0.04 m from the joint axis, what is the change in joint torque applied by the biceps brachii from 15 deg to 30 deg 9.0 Nm
What is the total energy of the segment, given that mass = 4.3 kg; g=9.81 m/s2; Vx= 0.18 m/s; Vy= 3.45 m/s; moment of inertia = 0.07234 kgm2; angular velocity = 6.3 rad/s; and height of center of mass= 0.39m 43.55 J
What is the work done on the segment given the following information?
(CHT 11 # 23)
20.78 J
During a knee extension exercise, the knee extensor muscle group is applying a torque of 230 N in an isometric contraction against the machine pad. If the knee joint angle is being held at an angle of 40 deg below horizontal and the machine pad is 0.35 m from the knee joint, how much force is being applied at the pad? 657.14 N
While exercising, an athlete holds a position with 90 deg of flexion at the hip joint and 90 deg of flexion at the knee joint. Considering only the ilosoas msucle group determine the amount of force neccassary to maintain this position, given the moment arm of ilopsoas = 10.5 cm from hip joint, mass of the lower extremity = 11 kg, and the moment arm of Cm of the lower extremity = 38 cm from the hip joint 39.81 N
During walking, the knee joint generates 50 Nm of extensor force during the same interval of the stance phase when the knee joint moved from 0.14 rad of flexion to 0.2 rad of flexion in 0.02 s. Determine the power of the knee joint muscles - 150 W

First Time Here?

Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.