Priest Final part 2 Biomechanics
What is the power output required for a 186 lb athlete to lift 200 lb a distance of 2ft in 1 second (ft x lbs per sec)?
400
How much work is accomplished by moving 200kg a distance of 200m?
40000 kgm
What is the velocity of an object (in ft/sec) which has free-fallen for 1.41 second?
45
If a 2nd class lever has a FA longer than the RA, what's the advantage (gain)?
Force
In a first class lever, if the fulcrum is closer to the force
a, c, and d
Identify a possible solution if the force on a 3rd class lever does not overcome the resistance.
any of these
Identify a first class lever; fulcrum is
between force and resistance
How far will a shot-put dropped off of the football stadium bleachers fall in 4.5 seconds?
both b and d
Others factors equal, which is more stable?
both c and d
If the resistance arm in a 3rd class lever is 10x the force arm
distance decreases 10x
Identify units expressing power output
kgm per min
How much work is done by moving 100kg a distance of 10m?
1000kgm
In the 1st class lever, the fulcrum is in the center -- what is the result of a 100kg force applied thru 2m distance?
100kg-2m opposite direction
A punter has a "hang-time" of 5.3 seconds; to what weight (in feet) did the ball go?
112
During elbow flexion, what force must be generated by the biceps to lift a 25 kg dumbbell if the FA is .1m and the RA is .5m?
125kg
How far will a shot-put fall in 1 second?
16 feet
Quantities which have both magnitude and direction are called
Vectors
What is the velocity (ft/sec) of an object which free falls for 6 seconds?
192
Elbow extension is an example of what lever and advantage?
1st class, distance advantage
What class lever and what advantage is demonstrated by the elbow during tricep extensions?
1st class/distance
What class of lever and what advantage is demonstrated by the quarterback's elbow throwing a forward pass?
1st class/distance
A resultant is a term to describe the combined effect of
2 or more vectors
In this 2nd class lever, the FA is 10x the RA -- what is the result of a 100kg force applied for a distance of 1m?
1000kg -.1m
What is the power output during lifting a 220 lb barbell 2m in 2 seconds(kgm per second)?
100
If the force arm is 10x longer than the resistance arm in a 1st class lever, how much force is needed to move a 1000 lbs?
100 lbs
In a 1st class lever, if the resistance arm is the same length as the force arm, how much force is needed to move 100 lbs?
100 lbs
How much force is needed to bench press 200 lbs?
200 lb
A ball was dropped from the top of the Astrodome and took 3.9 seconds to hit the ground. From what height was it dropped?
243 feet
What class lever and what advantage is demonstrated by the ankle (heel raises) during the standing squat?
2nd class/force
What is the average power output of a 75kg athlete to run 400m in one minute (kgm per minute)?
30000
What class lever is represented by elbow flexion?
3rd class
Knee extension is what class lever and what advantage?
3rd class lever, distance advantage
What class lever and advantage is demonstrated by the elbow during biceps curl?
3rd class/distance
What class lever and advantage is demonstrated by the wrist of the basketball player shooting a jump shot?
3rd class/distance
What class lever and what advantage is demonstrated by the knee during the hamstring curl?
3rd class/distance
What class lever and what advantage is demonstrated by the shoulder during the bench press?
3rd class/distance
What class of lever and advantage is demonstrated by the knee kicking a ball?
3rd class/distance
A golf ball was hit with a 9 iron and stayed in the air 3.5 seconds. What height (in feet) did it reach?
49
During knee extension, the RA is 10x the FA -- what is the result of the quads contracting w/ a force of 500 kg for .1m
50kg -1m
A ball reaches a height of 155 ft, how long it will be in the air (sec) from when it was kicked to when it hits the ground?
6.2
An arrow shot straight up to a height of 152 feet will stay in the air how many seconds?
6.2
Velocity is distance per unit of time (v=s/t); what is the average velocity of a sprinter who runs 220 meters in 20 seconds?
660 meters per minute
A golf ball was hit with a 3 iron and was in the air for 4.3 seconds. What height did it reach?
74 feet
What is the power output of a 110 lb athlete to jump over a .5m high bar 30 times in a minute (kgm per minute)?
750
What is the initial vertical velocity of a punt which has a "hang time" of 4.8 seconds (v=at)?
77 ft/sec
The acceleration (a) of a free falling object is 32 ft/sec/sec. What is the initial- vertical velocity (v) of a punt which has a "hang time" of 5.5 seconds (v=at)?
88 ft/sec
What is the total distance traveled (in meteres) for an object which has dropped for 4.3 seconds?
91
A golf ball was hit with a 6 iron and was in the air for 4.8 seconds. To what height did the ball go?
92
With a 1st class lever, identify a possible solution if the force does not overcome the resistance?
Bigger force and/or longer FA
When the study of mechanics is limited to living things, especially the human body, it is called
Biomechanics
Vectors may be combined by
only b and c
