Chapter 2.1 - Kinematics

Question 1

Kinematics: The physics of energy transfer.

(2) : @ rest @ motion

Answer 1

The energy at rest = potential

Once starts to move (the potential energy becomes) = kinetic (in motion)

Question 2

What determines the severity of an injury?

Answer 2

The amount of force that the body absorbs

Question 3

Term - Biomechanics

Answer 3

The general study of forces and their effects on a living body

Question 4

Term - Kinematics

Answer 4

The study of pure motion

Question 5

Mechanism of injury

Answer 5

How external energy forces in the environment are transferred to the body

Question 6

Newton’s first law

Answer 6

A body at rest will remain at rest (potential energy) and a body in motion (kinetic energy) will remain in motion UNLESS acted upon by an object.

• When energy is transferred it can occur on one of both objects.

For example - A car parked (potential energy) is being held in position by gravity. When impacted by another object e.g. car it sets it into motion. The vehicle will remain in motion until acted upon by ANOTHER object e.g. tree

Question 7

Newtons second law

Answer 7

FORCE is increased = acceleration is increased

Mass in increased = acceleration
is decreased

Question 8

Newtons second law - calculation

Answer 8

Fnet = mass x acceleration

Question 9

Newton’s third law of motion

Answer 9

For every action (energy impact) there is an equal and opposite reaction resulting from the transfer of energy.

Question 10

3rd law -Which is greater size or force?

Answer 10

Neither > for each force there is an equal and opposite reaction

Question 11

Law of conservation of energy

Answer 11

Energy can not be created or destroyed - only transferred from one thing to another

Question 12

Putting it all together - CAR CRASH

Answer 12

Car vs Tree

• According to newtons law of conservation of energy, a car travelling at 60 mph (kinetic energy) collides (transferring its energy), thereby creating an equal and opposite reaction that causes the vehicle to suddenly stop.
• However, the driver will continue to travel at the same speed until impacted by another force e.g. steering wheel, or windshield. This transfers the energy from the person onto that object.
• Although the body has stopped. the organs remain in motion until impacted by an object. e.g. collide with another stationery force e.g. spine