Gen Sci 9/20/26

Mechanics

the study of

an object's motion and

the force acting on it.

Statics

deals with forces

on objects that are in

equilibrium.

Dynamics

deals with the

motion of objects that are

accelerating.

Kinematics

focuses

on how objects move.

QUANTITIES:

· Displacement

· Time

· Velocity

· Acceleration

Kinetics

deals with

the forces that cause

change in motion. It

studies why an object

moves.

REFERENCE POINT

It is a specific location or object

used to describe how an object

changes in position.

It is typically set at any

fixed point of a coordinate

system which is important in

describing a motion.

SCALAR QUANTITY

described

only by its magnitude.

VECTOR QUANTITY

described by

both its magnitude and direction.

Translational motion

the movement of an object along a straight line.

Linear Quantities

· Distance (m)

· Displacement (m)

· Speed (m/s)

· Velocity (m/s)

· Acceleration (m/s2)

Rotational motion

the movement of an

object around an axis of rotation. This is also

known as angular motion.

Angular Quantities

· Angular displacement (0)

· Angular velocity (w)

· Angular acceleration (a)

Measured in:

· Radians (rad)

· Radians per second (rad/s)

· Radians per second squared (rad/s2)

Oscillatory Motion

the back-and-forth

motion of objects within an equillibrium/

central point, original position.

Periodic Motion

refers to

motion in a repeated interval

of time.

Contact forces

are

those that requires

direct physical contact

between objects, e.g; friction, tension

Noncontact forces

are

those do not require

direct physical contact

between objects, e.g; strong and weak nuclear force, electron force, gravity

. Linear Motion: Displacement (triangle X/Y, km/miles)

is the change of position from its initial position to its final position

- it can be observed within a specific direction.

ANGULAR DISPLACEMENT (Θ, degree and revolution)

It is the angle of movement of the moving object or

body measured in radian units (degrees, revolutions)

and is determined by both the radius of the circle and

the arc length.

The longer the __________, the greater the

radius and arc length of the

circular path of the object.

LINEAR VELOCITY (V, m/s or km/h)

Change in Displacement over Time. It is classified as either instantaneous velocity

(velocity at a specific time interval) or average

velocity (total net displacement throughout the total

time).

ANGULAR VELOCITY (W, rad/s or rpm)

This is expressed in either radians per second (rad/s) or

revolution per minute (rpm).

. along the axis of rotation.

Acceleration

rate at which velocity changes over time

LINEAR ACCELERATION (a)

The rate of change in linear velocity over time.

· expressed in meter per second squared (m/s2).

ANGULAR ACCELERATION (a)

Indicates the overall change of

angular velocity over time.

· expressed in units such as

radians per second squared

(rad/s2).

THE LAW OF INERTIA

. Explains how an object's

mass relates to its ability

to resist motion (inertia).

. The greater the object's

mass, the greater the

inertia.

THE LAW OF ACCELERATION (F = ma)

. Establishes the relationship between

force, mass, and acceleration.

. This law states that the net force

acting on an object is equal to the

product of its mass and

acceleration.

TORQUE

. a vector quantity.

. refers to the rotating force that

causes the rotational motion of

an object around its axis.

. determined by the magnitude of

the force applied and the distance

from the axis of rotation.

· measured in newton-meters (N.m).

THE LAW OF INTERACTION

· Explains action-reaction

pairs.

. This law describes how every

exerted force, there is an

equal and opposing reaction

force.

BiOMECHANiCS

. the study of how

mechanical quantities

influence the movement

of living organisms.

· common human

movements: exercise,

dance, and gymnastics.

ERGONOMiC DESiGNS

. the science of designing

a product or system that

fits the anatomical,

biomechanical, and

physiological

characteristics of a

person.

WORK

explains the relationship

between an applied force and

the displacement caused by

the exerted force, resulting in

energy transfer
-In ideal machines,

____ input is equal to

the ____ output

SIMPLE MACHINES

- basic mechanical devices that change the

magnitude or direction of force to make

work easier

- categorized into two groups:

Lever Group Inclined Plane Group

LEVER

- any object with a flat surface (rigid

bar or beam) that pivots at a fixed

point (fulcrum)

- relies on torque

First-class levers

fulcrum is between the effort and load

Second-class levers

load force is between the fulcrum and

the effort force

Third-class levers

effort force is between the fulcrum and

the load force

WHEEL

AND AXLE

- composed of a larger circular disk

that rotates along with a

smaller rod

PULLEY

- made up of a

grooved wheel

with a rope or

wire that moves

with it

Fixed Pulley

pulley remains stationary while the rope

moves

Movable Pulley

rope is attached to a fixed point, the

pulley is attached to the load, and the

end is free

INCLINED

PLANE

- any plane surface that is

positioned at a specific angle

WEDGE

- combination of

two inclined planes

placed back-to-back.

SCREW

- a special type of

an inclined plane

that is wrapped

around a core.

COMPOUND

MACHINES

- machines that combine two or

more simple machines to

perform a specific function

Ideal Mechanical Advantage (IMA)

- theoretical maximum possible

mechanical advantage of a machine
= distance of the effort/distance of the load resistance

Actual Mechanical Advantage (AMA)

- measured once the machine has

already performed a specific amount of

work with regard to the force applied

= load resistance force/effort force

EFFICIENCY

of a machine

- expressed as the percentage ratio of the actual

mechanical advantage over the ideal mechanical

advantage
= AMA/IMA x 100%

First-class levers

IMA=/</>1

Second-class levers

IMA > 1

Third-class levers

IMA < 1

IMA of Fixed Pulley

IMA = 1

IMA of Movable Pulley

based on the number of rope

segments that support the load

e.g. A movable pulley with two rope

segments has ___ = 2

= radius of the wheel/radius of the axle

IMA of Wheel and Axle

= length of the plane/height of the plane

IMA of Inclined Plane

= Length of the wedge slope/thickness of the wedg

IMA of Wedges

2π(radius)/pitch

IMA of Screws

MECHANICAL ADVANTAGE

of

COMPOUND MACHINES

obtained by multiplying the individual

mechanical advantages of the simple

machines that comprise it

fluid

is any substance that can flow

and take the shape of its container.

LIQUIDS

GASES

two types of fluids

LIQUIDS

Particles stay close together

Have a definite volume

Take the shape of their container

Example: Water, oil, milk

GASES

Particles stay far apart

Have no definite shape or volume

Expand to fill any container

Example: Air, oxygen, helium

Density (p) Unit: kg/m3 or g/mL

the ratio of how much mass is present

over a given volume of the fluid sample, indicator of how many

molecules or particles are compacted

within the given volume of the fluid.

P = m/v (mass over volume)

formula for density

Specific Gravity (SG)

. the specific ratio of the density of a

fluid to that of water (p = 1.00 g/mL).

SG = density of fluid/density of water

formula of Specific Gravity

specific gravity less than 1

will float

specific gravity more than 1

will sink

Pressure (P)

Units:
atmosphere (atm)

millimeter of mercury (mmHg)

newton per square meter (N/m2)

SI Unit for Pressure - pascal (Pa)

. the total amount of force applied across

a given area.

P = force/area

formula for pressure

DIASTOLIC PRESSURE

Is measured between beats

when the heart relaxes

SYSTOLIC PRESSURE

Is measured between when

the heart contracts

pressure will be greater if the force applied to an area is small/er

the relationship between area and force

Hypertension

occurs when the

excessive buildup of plaque in the

arteries constricts the blood

vessel, thus increasing the

pressure

. Hydrostatic Pressure (pressure by

a fluid at rest)

influenced by density and depth.

____________________ increases

as depth increases with respect

to Earth's acceleration due to

gravity (g = 9.8 m/s2)

P = pgh (p = density, g = gravity, h = depth)

formula for hydrostatic pressure

depth goes up, pressure goes up

relationship between depth and pressure

Viscosity

the measure of how a fluid is able to

resist flowing. “fluid thickness”

FLUID DYNAMICS

explores the interaction of various fluid properties.

PASCAL'S PRINCIPLE

principle that says pressure applied to a confined fluid is transmitted

throughout the fluid

P1= P2

input pressure = output pressure

F1/A1 = F2/A2

input force/area of input piston = output force/area of output piston

formula of pascal’s principle

ARCHIMEDES’

PRINCIPLE

principle that says an object submerged in a fluid

experiences an upward buoyant

force. The buoyant force is equal to

the weight of the fluid displaced by

the object.

1. High-density fluids tend to exert a higher

buoyant force.

2. The amount of fluid displaced is an

indicator of the buoyant force present.

3.An object will experience a greater

buoyant force if it is placed on an area

with higher gravitational force of

attraction.

FACTORS THAT AFFECT BUOYANT FORCE

1. Shape - affects how much fluid an

object can displace.

2. Mass - affects the object's weight.

3. Volume - affects the amount of fluid

displaced.

FACTORS THAT CAUSE AN OBJECT TO FLOAT

SERIES connection

· composed of a single

linear pathway

. found in flashlights,

traditional Christmas

lights, and basic

alarm systems

- less reliable

PARALLEL connection

· made up of multiple

pathways

. usually found in

household and

industrial electrical

systems

- more reliable

AMMETER

used to measure the electric

current in a circuit

VOLTMETER

used to measure the voltage in a

circuit

ELECTRICAL FUSE

used to stop the electrical flow

once overcurrent has been

detected, but is only single use

CIRCUIT BREAKER

used to stop the electrical flow

once overcurrent has been

detected, but can be reset

ELECTRICAL

HAZARDS

any condition driven by

electricity that may impose

harm to human upon exposure

OVERLOADING

. occurs when many electrical devices

are loaded in a given circuit

. overcurrent takes place and may lead

to overheating, leading to electrical

fires

DAMAGED

INSULATION

· insulation materials covering electical

wires are damaged due to gnawing of

animals, overheating, wear-and-tear

FAULTY WIRING

. due to poor electrical installation and

maintenance, weakening due to the

passing of time, or changes in

environmental conditions that can

lead to electrical hazards

DAMP ELECTRICAL

CONDITIONS

environments and

electrical power are highly hazardous

combinations due to water being an

efficient conductor of electricity

increases risk of electrical shock,

electrocution, or short circuit

ELECTROCUTION

. death or severe injury caused by an

electric shock

· magnitude of current has varying

effects depending on voltage,body

impedance, and length of exposure

may affect muscle functioning,

ventricular fibrillation, burns

Ground Fault Circuit Interrupter (GFCI)

automatically turns off electrical

power when ground fault occurs

ELECTRICAL FIRES

. occur due to overheating, faulty

electrical wiring, or short circuits

· Generation

- production of electricity

· Transmission

- transportation of electricity over long

distances

. Distribution

- delivery of electricity to consumers

generator

a device that

converts mechanical energy into

electrical energy through the

movement of turbines.

Alternating current (AC)

is primarily used in generators

because it is more cost-effective

and requires little maintenance

Energy Source -> Mechanical Energy -> Turbine -> Generator -> Electrical Energý

how is electricity generated