Final Exam

Question 1

When lifting a hand box or a barbell off the floor, which joint or body part, would you want to minimize torque Where would you want maximize torque

Answer 1

Minimize the flexion torque on the L5 -S1 to promote safety, maximize torque at the hip joint

Question 2

The point around which a bodies weight is equally balance in all directions is known as what?

Answer 2

center of gravity

Question 3

Is it easier to push or pull a desk across the classroom floor why?

Answer 3

Pull, you are reducing resistance by decreasing weight as opposed to pushing you are increasing resistance you are adding weight

Question 4

The rotary effect of a force about an axis of rotation is known as what?

Answer 4

Torque/moment

Question 5

What is a forced couple?

Answer 5

A pair of equal opposite forces

Question 6

What is the difference between balance and stability?

Answer 6

Stability is a resistance to distribution of equilibrium, whereas balance is an ability to control equilibrium

Question 7

What does newtons first law in angular kinetic state?

Answer 7

Rotating body will continue to turn about its axis of rotation, with constant angular momentum, unless an external eccentric force is exerted upon it

Question 8

When we mentioned in class to increase stability

Answer 8

Increase mass, increase friction, increase size of support

Question 9

How does kinetic energy and potential energy change during a project child in motion?

Answer 9

Ascension -potential energy increases, kinetic decreases
Apex - potential energy at its highest, kinetic equals zero
Descent - potential energy decreases, kinetic energy increases

Question 10

Why is this carnival game with the ladder so difficult to win ?

Answer 10

Your body center of gravity has to be aligned with the letters center of gravity, which is a narrow straight line and that line will cause you to fall off the ladder

Question 11

What is the difference between mass and weight?

Answer 11

Weight implies gravity

Question 12

Why would it hurt more getting punched in the face closed fist with the force of 250 and compared to getting slapped open palms in the face in the same spot with the same amount of force?

Answer 12

More pressure with close fist due to less surface area (P=F/A)

Question 13

First class lever

Answer 13

Force and resistance on opposite sites of axis of rotation

Question 14

Second class lever

Answer 14

Force and resistance acting on the same side or resistance is closer to the axis of rotation

Question 15

Third class, lever

Answer 15

Force arm closer to axis of rotation resistance, being further away

Question 16

What is a mechanical advantage?

Answer 16

Is a measure of the force amplification achieved by using a tool
Mechanical advantage = force/resistance

Question 17

How does the patella increase mechanic advantage?

Answer 17

Increases the forearm between tendon and axis of rotation

Question 18

What is static equilibrium?

Answer 18

Emotionless state in which there is no net force or net torque acting

Question 19

Balance method

Answer 19

The weight and vertical reaction force at the fulcrum must lie in the same way

Question 20

Inertia (linear)

Answer 20

• An object or bodies characterize, but its resistance to changes and its current state of motion
• deals with mass
• The more mass body has the more inertia it’s going to happen

Question 21

Angular inertia (rotation)

Answer 21

• Object, your body resistance to angular acceleration
• mass + distance is distributed from the axis of rotation

Question 22

Moment of inertia

Answer 22

Some of the products of each particles mass and the radius of rotation for the particles squared

Question 23

What is the radius of gyration ?

Answer 23

Distance from the axis of rotation to a point where the bodies mass could be concentrated without altering its rotational characteristics

Question 24

What is angular momentum?

Answer 24

• Quantity of angular motion possessed by a body
• measured as the product of moment of inertia and angular velocity

Question 25

What produces change in angular momentum?

Answer 25

Angular pulse changes in angular momentum equals to the product of torque and time interval over which the torque acts