Energy
The unit for energy is the
Joule
Temperature
Wave are divided into two broad categories based on what states of matter they can travel through
Electromagnetic and mechanical waves
Machines are designed to make work...
easier
How much work is required to move a cart with 500 Newtons of weight a distance of 5 meters?
A transfer of energy is termed
Work
When thermal energy transfers from one object to another, this is termed
heat
The color of an object tells us about what wavelength(s) it __________.
reflects
A machine that requires more force over less distance is termed a _________ advantange machine
Distance
100 Watts
The two broad categories of energy
Kinetic and potential
This type of heat transfer comes in the form of electromagnetic waves, originating from the sun
This type of wave behavior causes waves to bend around an object, and can be increased by making the waves larger or the barrier opening smaller.
Wave diffraction
Lever
Most modern Wi-Fi routers operate at a frequency of 2.4 GHz (2,400,000,000 Hz). The wavelength of these invisible electromagnetic waves is approximately 0.125 meters. What is the speedof the Wi-Fi waves?
Wave speed (v) = frequency () x wavelength ()
v = 2,400,000,000 Hz * 0.125 m = 300,000,000 m/s
This type of energy is relative to the height at which an object is located
Gravitational Potential Energy (GPE)
Sidewalk squares are separated by cracks because of this law
The Expansion and Contraction Particle Theory
This type of wave on the electromagnetic spectrum is responsible for heating the earth, and even plays a role in remote control usage.
Infrared waves
How much easier a machine makes your work is called its
Mechanical advantage
A roller coaster stops at the top of a large drop. The height at the top is 120 meters. The cart itself, with all its passengers, weighs 1500 kilograms. What is the gravitational potential energy at the top of the drop?
GPE = mass x gravity x height => 1500 kg * 9.8 * 120 m = 1,764,000 Joules of GPE
This law, discovered by James Prescott Joule, explains how energy cannot be created or destroy, rather transformed into different types of energy.
The Law of Conservation of Energy
An iceberg has more thermal energy than a hot cup of coffee because thermal energy relies on both of THESE things
Kinetic energy of particles and number of particles
This Greek letter is used in physics to mean "wavelength"
lambda (λ)
The percentage of useful output work compared to the input work you put in is termed this, and it is best to hvae over 50% in order for machine to be useful.
Efficiency
A roller coaster's total mechanical energy (TME) is conserved throughout a ride at 1,500,000 Joules. At the lowest point of the roller coaster, the GPE is 14,500 Joules. What is the kinetic energy (KE) at this point?
KE = 1,500,000 J - 14,500 J = 1,485,500 J of KE