Bio Mechanics

The maximum limiting friction that can be generated between the bag and the cart is 50 N. You need to slide the bag to the side of the cart. If you apply 50 N horizontally on the bag,

the bag will remain motionless

Poisson's ratio refers to

the ratio of strain in the axial direction to strain in the transverse direction for each different type of material

A load that produces twisting of a body around its longitudinal axis is called a:

torsion load

If a runner completes a 400-meter sprint around a 400 m track in 50 seconds, what is the runner's displacement with respect to the starting position?

0m

Ariel is running a 100m dash. When the start pistol fires, she leaves the starting block and continues to speed up until she reaches her top speed of 10m/s 4s into the race. She holds this speed for 4s and then gradually slows down until she crosses the finish line 10s after she started the race. What is Ariel's average velocity for the whole race? Possible formulas: v=d/t a=v/t

10m/s

George runs the football 15 yards straight downfield then 5 yards to the right before he is tackled. What was George's resultant displacement in yards?

15.8 yards

A high jumper with a body weight of 900 N exerts an average vertical force of 1780N down on the floor for 0.75 s. The average vertical force exerted on the jumper by the floor is:

1780N

Ariel is running a 100m dash. When the start pistol fires, she leaves the starting block and continues to speed up until she reaches her top speed of 10m/s 4s into the race. She holds this speed for 4s and then gradually slows down until she crosses the finish line 10s after she started the race. What is Ariel's average acceleration during the first 4s into the race? Possible formulas: a=(vf-vi) / t F=ma

2.5m/s2

A 75kg weightlifter exerts a 1300 N force upward against a 175lb barbell. How large is the net vertical force acting on the barbell?

522N

The coefficient of dynamic friction between the grass and a 150 kg football blocking sled is 0.40. If a 100 kg football player only pushes horizontally against the sled, how large must the horizontal force be to keep the sled moving at constant velocity? Possible formulas: Fd=udR F=ma

589N

A 250lb shot-putter pushes forward and upward on a 5kg shot with a force of 1200N. This force acts at an angle of 40° above horizontal. How much of this 1200N force acts in the upward direction?

771N

Please Match the following movements with their corresponding plane. Shoulder abduction

Frontal/Lateral/Coronal

Identify the true statement.

Increasing the magnitude of a force acting on a surface area increases the amount of stress acting on the surface.

Please Match the following movements with their corresponding plane. Knee Flexion

Sagittal/anteroposterior

The research on the tension-length relationship of muscles indicates that a muscle is capable of generating maximal force when the muscle is

slightly longer than resting length

The horizontal velocity of Serena's tennis serve is measured as 75m/s. Horizontally, the ball travels 25 m before reaching her opponent. If the ball didn't slow down when it bounced or because of air resistance, how long would it take to reach her opponent? Possible formulas: v=d/t F=ma

0.33s

The study of the forces that cause of tend to cause motion is called

kinetics

George runs the football 15 yards straight downfield then 5 yards to the right before he is tackled. What was George's distance traveled in yards?

20 yards

An 80 kg volleyball player lands from a jump and tries to stop her forward motion. The normal contact force exerted by the floor on her shoes is 2000 N. The friction force exerted by the floor on her shoes is 600 N acting backward on the player. What is the resultant ground reaction force exerted by the floor on the volleyball player's shoes?

2088N

The coefficient of static friction between the sole of an athletic shoe and the basketball court floor is 0.75. Bill wears these shoes when he plays basketball. If Bill exerts a normal contact force of 1275N when he pushes off the floor to run down the court, how large is the friction force exerted by his shoes on the floor? Possible formulas: Fs=usR F=ma

956N

As the velocity of a concentric contraction increases (such as throwing a ball), the maximum force a muscle can produce increase - in other words, the faster your arm can move to throw a ball, the more force the arm muscles can exert on the ball.

False

Identify the true statement?

Increasing the surface area over which a force is distributed decreases the amount of stress acting on the surface.

If you increase the time during which a constant force is applied to an object, what effect does this have on the impulse given to the object?

It increases the impulse

The principle of conservation of momentum restates

Newton's first law

A ball being held by someone running will continue to move in the same direction and with the same speed until the runner causes a change in motion of the ball. This best exemplifies

Newton's first law of motion

Please Match the following movements with their corresponding plane. Hip Rotation

Transverse/horizontal

When performing a vertical jump for maximal height, muscle spindles and Golgi tendon organs play a significant role in explosiveness. Why does jumping following a quick squat allow for greater height than jumping after holding a squat for a few seconds?

When going into a quick squat, muscle spindles are recruited and their response is muscle contraction

If you fracture your femur, you will be told by your medical provider to start to weight bear as soon as the fracture site closes because of what guiding principle?

Wolff's law

The force that acts parallel to an object in contact with a surface and may result in the formation of blisters is called

a shear force

When a sprinter uses starting blocks to enhance running performance, which of Newton's laws is best represented by the interaction of the sprinter's feet and the blocks as they push off?

action-reaction

When performing a biceps curl, the biceps brachii is the ____________ while the triceps brachii is the ______________.

agonist, antagonist

The left fielder throws the baseball home from 60 m away. The ball's horizontal velocity is 30 m/s, and its vertical velocity is sufficient to keep it in the air until it reaches the catcher at home plate. At the same time, a base runner is running toward home plate. His velocity is 5 m/s, and he is 5 m from home plate. If the base runner's velocity stays constant and air resistance isn't a factor, which will arrive at home plate first, the base runner or the baseball and why? Possible formulas: v=d/t a=v/t

baserunner; takes 1 second to reach home plate

Bone is strongest in resisting

compressive stress

When articular cartilage is exposed to constant compressive stress, the strain in the cartilage will increase gradually with time. This concept is called

creep

Kinematics is the branch of mechanics that:

describes the pattern of motion

While walking and then running at a constant speed with the same ball, you want to release each ball in time for it to land in a target. In order for the ball that you run with to hit the target, when would you have to release the ball you run with relative to the release of the ball you walk with?

earlier than the ball you walk with

When going down into a squat, the quadriceps muscles control the movement at the knee via _____________________ contraction.

eccentric

When a you stretch your hamstrings and they return to their original pre-stretch length upon release, it is called

elastic

Muscles have the unique properties of extensibility, contractility, elasticity, and

excitability

If a bag has a mass of 25 kg, how much force must you apply vertically to lift it off of a baggage cart?

greater than 245 N

While running at a constant speed with 2 balls of different weights, you drop the balls at the same time while running past a target. Both balls continue to move in the same direction as the runner upon release as they descend to the ground. Assuming air resistance is negligible, why do the balls hit the ground at the same time?

law of universal gravitation

What type of bone is the fibula?

long

Which quantity is the same in space as on the earth?

mass

While running at a constant speed with 2 balls of different weights, you drop the balls at the same time while running past a target. Both balls continue to move in the same direction as the runner upon release as they descend to the ground. Why do the balls keep moving in the same direction as the runner upon release?

momrntum

When a you stretch your hamstrings and they then assume a new "normal" lengthened position upon release, it is called

plastic

Which of the following joint types is the 1st carpometacarpal joint?

saddle/sellar