Physics is basically the study of how and why things in the universe behave the way they
do. It covers things like motion, forces, energy, electricity, light, heat, waves, and even atoms.
Mechanics is one major branch of physics. It focuses specifically on motion and the forces
that cause or change motion.
A simple way to picture it:
Physics​
→ Mechanics​
→ Electricity & magnetism​
→ Waves & sound​
→ Thermodynamics​
→ Optics​
→ Modern/quantum physics, etc.
Within mechanics, you usually learn a few main areas:
●​ Kinematics: describing motion without worrying about what causes it. This includes
position, displacement, velocity, acceleration, and equations like​
vf=vi+atv_f = v_i + at
●​ Dynamics: looking at the forces that cause motion. This is where Newton's laws come
in, especially​
F=maF = ma​
So if you apply a larger force to the same object, it accelerates more.​
●​ Statics: objects that are not accelerating. For example, a bridge sitting still has forces
acting on it, but those forces balance:​
∑F=0\sum F = 0
●​ Energy and work: instead of analyzing forces directly, you can often look at how energy
changes. For example,​
KE=12mv2KE=\frac12mv^2​
is kinetic energy, and​
PE=mghPE=mgh​
is gravitational potential energy.​
●​ Momentum: useful for collisions and impacts:​
p=mvp=mv​
In many situations, total momentum before a collision equals total momentum afterward.​
●​ Rotational mechanics: basically the rotational version of regular mechanics. Instead of
force, you deal with torque. Instead of mass, you often deal with moment of inertia.
This becomes really important for things like joints, wheels, gears, and human
movement.
For example, imagine you're analyzing someone doing a bicep curl. Mechanics could help you
determine the force produced by the biceps, the torque around the elbow, how the dumbbell's
weight affects the joint, and how changing the arm angle changes the required muscle force.
That's also why mechanics becomes really important in biomedical engineering. You can use
it to understand bones, joints, muscles, prosthetics, implants, wheelchairs, medical devices, and
biomechanics.
The biggest idea to remember is:
Kinematics tells you what the object is doing. Dynamics tells you why it's doing it.
If you want, I can also teach you physics/mechanics from the absolute basics, like a mini
first-year university lesson starting with displacement, velocity, acceleration, forces, and
Newton's laws.