Relationships among energy, force and

motion

PHYSICS

Spread of Energy

Energy spreads in all direction from an energy producing source.

Energy spreads much like the ripples in this water.

Wavelength

The wavelength determines the amount of energy.

Short wavelengths have a higher energy.

Long wavelength have a lower energy.

Sound

Sound waves require a medium to travel through. Sound does not travel in a vacuum.

High frequency sounds are higher pitched.

Low frequency sounds are lower pitched.

The volume is how intense the sound is.

Response to Sound

Elephants can hear very low frequency sounds for miles (infrasound range.

Sound waves vibrate a thin membrane on the cricket’s front legs.

Sound Technology

Ultrasounds use the reflections of high frequency sound waves to construct an image of a body or ogans.

Heat

Heat transfer in three different ways Conduction- Heat transfers from one object

to another that are in contact.The spoon heats because it is in hotsoup.

This transfer happens

by movement of currents due to differences in Electromagnet

waves densities. Hotter particles directly transfer thisAre less dense. heat through

space.

Response to Heat

Cold-blooded creatures take on the temperature of their surroundings.

To generate heat, warm-blooded animals convert the food they eat into energy.

Heat Technology

A thermographic camera is a device that forms an image using infrared radiation.

Electromagnetic Spectrum

Visible Light

All energy in the electromagnetic spectrum travels at the same speed 186,000 miles per second.

Wavelength is what determines the type of energy.

Visible light is only a small part of the spectrum.

Visible light is separated into the colors of the rainbow.

Visible Light Spectrum

When white light shines through a prism, that light is broken into the part of the visible light spectrum.

Each color corresponds to a different wavelength.

Response to Light

The dragonfly eye contains 30,000 lenses to bend the light energy entering it.

The visual acuity of a falcon is 2.6 times better than a human.

Light Technology

Telescopes consist of an arrangement of lenses and mirrors that gather visible light permitting direct observation of distant objects.

Energy Types

Potential energy – energy an object has due to its position.

Kinetic energy – energy possessed by a body by virtue of it being in motion.

Types of Energy

Chemical energy Electrical energy

Light energy Nuclear energy

Heat energy

Mechanical energy Sound energy

Energy Conversion

The law of conservation of energy states that energy cannot be created or destroyed.

Energy can convert from one kind of energy to another.

Gravity

Gravity is a pulling force that is exerted on objects.

Gravity is an attractive force between all matter.

Mass versus Weight

Mass is the

amount of Earth

matter contained in an object.

Weight is the

measure of

the force of

gravity.

Moon

Gravitational Force

Gravitational force depends on the mass of the object.

Gravity pulls harder on the more massive object.

Gravitational Force

Gravitational force also depends upon the distance of the object.

Planets closer to the sun have a greater gravitational pull

Forces that result in motion

Motion is a change in action or position as a result of an unbalanced force.

Isaac Newton described the relationship between the forces acting on a body and its motion due to those forces.

Newton’s Laws of Motion

1 – Law of Inertia – An object at rest wants to stay at rest. An object in motion wants to stay in motion. 2 – F=ma – Force equals mass x

acceleration

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

Work

Work is using force to move something through a distance.

Simple Machines

Machines make work easier.

They all belong to the lever or inclined plane families.

Mechanical Advantage

How much easier and faster a machine makes your work is the mechanical advantage of that machine.

The mechanical advantage I the number of times the machine multiplies your force.

Mechanical advantage formulas

Lever Length of lever arm / length of resistant arm

Pulley number of ropes over the pulley

Wheel and axle Radius of wheel / radius of axle

Inclined plane Length of slope / height of slope

Complex machines

Complex machines are a group of simple machines that all work together to accomplish a task.