Mechanics External L2 Energy And Momentum

Front 1

GPE

Back 1

Gravitational potential energy, stored energy that an object has due to height above the ground.

Front 2

GPE size depends on...?

Back 2

The mass of the object, the strength of gravity and the height of the object above ground.

Front 3

GPE formula?

Back 3

∆Ep=mg∆h

Front 4

Kinetic Energy

Back 4

Energy an object has because it's moving.

Front 5

Kinetic energy depends on?

Back 5

The mass of the object and the speed it's traveling

Front 6

Stored spring energy

Back 6

A spring compressed or stretched tends to pull it push itself back to its equilibrium position. Until the spring is released and allowed to reach it, it has energy stored in it.

Front 7

The amount of energy in a spring relies on?

Back 7

The spring constant (stiffness of spring) and extension of the spring (compressing or stretching).

Front 8

Spring stored energy equation

Back 8

∆Ep=1/2kx^2

Front 9

Conservation of energy

Back 9

Energy can't be created or destroyed only be transformed from one form to another.

Front 10

What's an isolated system?

Back 10

Total energy and momentum in an isolate system remains constant. It is a system free from external forces.

Front 11

Dynamic Systems

Back 11

Are realistic systems that there will always be some energy losses. Most commonly due to resistance of frictional losses where some initial energy input is converted into heat and sound.

Front 12

Work

Back 12

Energy is the ability to do work. Work is an energy transfer, can be found using:

W=Fd

Front 13

Conditions of work done

Back 13

Force and distance travelled must be parallel, or have a parallel component. If an object is moved perpendicular to the force, then no work is done by the force on that object.

Front 14

Power

Back 14

Rate at which work is done. A measurement of how much energy is transformed per second.

Equation:

P=W/t

Front 15

Relationship between watts and energy

Back 15

One watt of power equates to 1 joule of energy being transformed per second.

Front 16

Momentum

Back 16

A vector an object has due to its mass md velocity. "Mass in motion". Objects with greater mass or higher velocity have more momentum and required a greater amount of force to stop them.

Front 17

Momentum equation

Back 17

p=mv

Front 18

Change of momentum

Back 18

Found through vector Subtraction.

Front 19

Change of momentum equation

Back 19

Equation: ∆p=pf-pi

Front 20

Impulse

Back 20

Concept relating an object's change in momentum to the force creating the momentum change md the time that the force is applied.

Front 21

Impulse note:

Back 21

Often questions to us on how in reading the time during which a collision occurs reducing the force experienced during tht collision. When solving these problems it is important that the change in momentum

(F x d) is constant for the two scenarios that are being examined.

Front 22

How variables effect Impulse

Back 22

Short period of time = larger force

Long period of time = smaller force

Front 23

Area under Force/Time graphs

Back 23

Under the curve represents the impulse

Front 24

Conservation of momentum

Back 24

"the total momentum before a collision (or explosion) is equal to the total momentum after the collision, unless acted upon by an external net force"

Front 25

What's an external net force?

Back 25

A force from something not initially considered to be part of the system.

Front 26

Momentum Total Equation

Back 26

PTotal=P(left)+P(right)

Front 27

If friction forces are large?

Back 27

Total momentum will not be conserved. COM is not broken because friction is an external net force.