Physics

Forces, mass, acceleration, and motion graphs. Example: $F=ma$, so $10\text{N}$ on $2\text{kg}$ gives $a=5{\text{m/s}}^2$.

3 lessons

Momentum $p=mv$ is conserved in collisions. Example: $4\text{kg}$ at $5\text{m/s}$ has $p=20\text{kg⋅m/s}$.

2 lessons

Objects moving in a circle need centripetal force. Example: $a_c=v^2/r=16/2=8{\text{m/s}}^2$.

2 lessons

Force between charges and the fields they make. Example: $F=k{q}_1{q}_2/r^2$ — doubling $r$ quarters the force.

2 lessons

Voltage equals current × resistance. Example: $V=IR$, so $5\text{V}$ across $10\Omega$ gives $I=0.5\text{A}$.

2 lessons

Changing magnetic flux induces an EMF. Example: $\epsilon =-N\Delta \Phi /\Delta t$.

2 lessons

Springs and pendulums oscillating. Example: spring period $T=2\pi \sqrt{m/k}$.

2 lessons

Reflection, refraction, lenses. Example: Snell’s law $n_1\sin {\theta }_1=n_2\sin {\theta }_2$.

2 lessons

Heat, work, and the first law. Example: $\Delta U=Q-W$ — heat in minus work out.

2 lessons

Wave speed = frequency × wavelength. Example: $v=f\lambda$, so $50\text{Hz}\times 2\text{m}=100\text{m/s}$.

2 lessons