Thermodynamics & Waves
Thermodynamics: Understanding Heat Energy and
Work
In physics, thermodynamics is the study of heat energy and the behavior
of systems when heat is added to them. The goal is to determine if we can
convert heat energy into useful work. Matter, such as gas, contains energy
in the form of moving atoms. This energy is measured as temperature.
When heat is added to a gas, the motion of the particles increases, leading
to a rise in temperature.
We want to figure out how to make the system, like a piston, do work for
us. Adding heat energy to a gas expands and pushes the piston up, which
is considered work. This concept is used in various applications, such as
steam engines and jet engines, where heat energy is converted into
motion and work. However, it's important to note that we can't get more
work out of a system than the heat energy we put in. This is known as the
first law of thermodynamics, which states that the work output can never
exceed the heat input.
The second law of thermodynamics also states that systems tend to
increase in disorder over time. Without any outside stimulus, a gas in a
container will naturally spread and fill the entire space. This law highlights
the tendency of systems to move towards greater disorder.
, Introduction to Physics, Part 3 (Electricity,
Magnetism, Quantum Mechanics & Relativity)
Electric fields can be compared to peanut butter and jelly; if electric
charges are the peanut butter, the electric field is the jelly. Imagine a
proton with a positive charge surrounded by an invisible field with radial
arrows that emanate from the charged particle instead of closed loops.
The relationship between electricity and magnetism was combined into a
single concept called electromagnetism in modern physics. A proton is
pushed in the same direction as the field lines, while another charged
particle moving through the field is pushed tangentially to the magnetic
field.
Theories of relativity and quantum mechanics were developed by many
scientists in the early 20th century, yet even today we struggle to fully
understand these theories. There remain many unsolved problems in both
relativity and quantum mechanics.
We can demonstrate that time travels at different rates for different
people. For instance, by using highly accurate atomic clocks onboard
airplanes, we observed that when we returned to Earth, clocks no longer
agreed as time takes varied time depending on how quickly you move.
Quantum Mechanics predicts that when we have a proton in an atom's
nucleus, electrons surrounding the nucleus do not behave like a solar
system going round and round as one might learn in a Chemistry
classroom.
The human transformation has evolved from basic survival instincts like
learning to make shelter and make a fire to developing technology to
communicate, advance medical imaging, calculate solutions, and even go
into space.
Without Quantum Mechanics, computer chips would not exist, and neither
would computer screens like Androids or iPhones.
, Review Of Essential Algebra, Part 1
Review of Essential Algebra
we will review the absolute most essential concepts in algebra that you
need to know in order to do well in physics. This is part one of two, so let's
get started.
The Number Line
Let's begin by reviewing the number line. The number line starts at 0, also
known as the origin or the middle point. It extends in both positive and
negative directions, with positive numbers going to infinity in one
direction and negative numbers going to negative infinity in the other
direction. We only consider the integer values on the number line for now.
Adding Positive Numbers
When adding positive numbers together, we simply move to the right on
the number line. For example, 3 + 4 equals 7. We start at 3 and move 4
units to the right to land on 7. The general rule is that when we add two
positive numbers, we always get a positive number as the result.
Adding Negative Numbers
Adding negative numbers can be a bit trickier. Let's consider the example -
1 + (-2). We start at -1 and need to add -2 to it. To do this, we think of
moving to the right on the number line, but since we are starting from a
negative number, we are actually moving to the left. So, starting from -1,
we move 2 units to the left and end up at -3. The result is -3. When adding
a negative number to another negative number, the result is always
negative.
, Review Of Essential Algebra, Part 2
Hello, welcome back to the physics course. In this review, we will be
covering essential concepts in algebra, including exponents, solving
equations, and graphing. If anything is unclear, feel free to revisit the
algebra course for a refresher.
Exponents
Exponents are used frequently in physics, both in problems and units. Let's
quickly review how they work:
When we have a number raised to an exponent, such as 3 raised to the
power of 2, it means we multiply the number by itself the specified
number of times. So, 3 raised to the power of 2 is equal to 3 multiplied
by 3, which equals 9.
Similarly, 2 raised to the power of 3 means we multiply 2 by itself three
times. So, 2 raised to the power of 3 equals 2 multiplied by 2 multiplied
by 2, which equals 8.
Exponents can be applied to any number, not just 3 and 2. For example,
147 raised to the power of 4 would mean multiplying 147 by itself four
times.
However, in physics, we commonly use exponents with powers of 10. For
instance, 10 raised to the power of 1 is simply 10, 10 raised to the power
of 2 is 100, and 10 raised to the power of 3 is 1,000. Each time we
increase the exponent, we multiply by 10.
It's also worth noting that exponents can be negative numbers. For
example, 10 raised to the power of -1 would mean dividing 1 by 10.
