Linear Kinetics

Question 1

Linear Kinetic

Answer 1

Study of the forces associated with linear motion

Question 2

Law of Gravitation

Answer 2

All bodies are attracted to one another with a force:

• Proportional to the product of their masses
• Inversely proportional to the distance between them

Question 3

Newton’s 1st Law

Answer 3

• Law of Inertia

- An object in motion or at rest will remain so unless acted on by a sufficient external force

Question 4

Newton’s 2nd Law

Answer 4

• Law of acceleration
• A force applied to a body causes an acceleration of that body
• F = ma

Question 5

Newton’s 3rd Law

Answer 5

• Law of Reaction

- For every action, there is an equal and opposite reaction

Question 6

Normal Reaction Force

Answer 6

Force acting perpendicular to 2 surfaces in contact

Question 7

Orthogonal

Answer 7

2 surfaces are perpendicular to each other

Question 8

Friction

Answer 8

A force that acts at the area of contact between 2 surfaces in the opposite direction of motion

Question 9

Static Friction

Answer 9

• Force acting over the area of contact between 2 surfaces

- Increases as the opposing force increases, but motion does not occur

Question 10

Maximum Static Friction

Answer 10

• Max amount of friction that can occur between 2 stationary surfaces in contact

Question 11

Kinetic Friction

Answer 11

• Constant magnitude friction generated between 2 surfaces in contact during motion
• Always less than max static friction

Question 12

Coefficient of Friction

Answer 12

• μ (mu)
• Unitless # indicating the relative ease of sliding or the amount of mechanical and molecular interaction between 2 surfaces in contact

Question 13

Static Friction Equation

Answer 13

F(s) = μ(s)R

Question 14

Maximum Static Friction Equation

Answer 14

F(m) = μ(m)R

Question 15

Kinetic Friction Equation

Answer 15

F(k) = μ(k)R

Question 16

Rolling Friction

Answer 16

• Friction between a rolling object and the surface on which it rolls
• Lower than sliding friction

Question 17

Linear Momentum

Answer 17

• The quantity of motion a moving body possesses

- M = mv

Question 18

Principle of Conservation of Momentum

Answer 18

In the absence of external forces, the total momentum of a given system remains constant

Question 19

Impulse

Answer 19

• Product of force and the time over which the force acts
• Change in momentum
• Impulse = Ft

Question 20

Impact/Collision

Answer 20

A collision between 2 bodies characterized by the exchange of a large force during a small time interval

Question 21

Perfectly Elastic Collision

Answer 21

• Collision during which the velocity of the system is conserved
• Ball will bounce to the drop height

Question 22

Perfectly Plastic Collision

Answer 22

• Impact resulting in the total loss of system velocity

- Object will not bounce at all

Question 23

Coefficient of Restitution

Answer 23

• Unitless number that serves as an index of elasticity for colliding bodies
• 0 = plastic
• 1 = elastic

Question 24

Coefficient of Restitution Equations

Answer 24

-e = (v1 - v2)/(u1 - u2)
- v = relative velocity after impact
- u = relative velocity before impact
e^2 = h(b)/h(d)
- h(b) = bounce height
- h(d) = drop height

Question 25

Law of Impact

Answer 25

When 2 bodies undergo a direct collision, the difference in their velocities after impact is proportional to the difference in their velocities before impact

Question 26

Direct Impact

Answer 26

Impact which is either "head on" or at right angles to the surface

Question 27

Oblique Impact

Answer 27

Impact which occurs at angles that are not perpendicular

Question 28

Work

Answer 28

- W = Fd | - 1 J = 1 Nm

Question 29

Positive Work

Answer 29

Net muscle torque and angular joint motion are in the same direction (concentric)

Question 30

Negative Work

Answer 30

Torque and motion are in the opposite direction (eccentric)

Question 31

Power

Answer 31

- Rate of work production - P = W/t - P = Fv - 1 W = 1 J/s

Question 32

Energy

Answer 32

The capacity to do mechanical work

Question 33

Kinetic Energy

Answer 33

- Energy of motion | - KE = 1/2mv^2

Question 34

Potential Energy

Answer 34

- Energy of position - PE = wt x h - PE = mgh - 1 J = 1 Nm

Question 35

Law of Conservation of Mechanical Energy

Answer 35

- When gravity is the only external force, a body's mechanical energy will remain constant - C (constant) = PE + KE + TE

Question 36

Strain/Elastic Energy

Answer 36

- A form of potential energy - Capacity to do work by virtue of a deformed body's return to its original shape - SE = 1/2kx^2