Forms of Energy

#energy

Kinetic Energy §

• $E_k$ or $KE$
• Energy due to movement of an object with mass
• $E_k=\frac{1}{2}m{v}^2$ (for speeds $<0.1\text{speed of light}$)
• Usually (like always, but only if you remove it lol), mass is conserved
• $\therefore \Delta v\to \Delta E_k$
• $\Delta E_k=\frac{1}{2}m(v_f^2-v_i^2)$ or $\Delta E_k=\frac{1}{2}m(v^2-u^2)$

Gravitational Potential Energy §

• $E_g$ or $GPE$
• Energy due to position in a gravitational field of an object with mass
• $E_g=mgh$

Springs §

k (the spring constant) = $\frac{F}{x}$ or the gradient of a F vs x graph

• Note: As the displacement is a square relationship in $U_s=\frac{1}{2}k(\Delta x{)}^2$, when two springs are at equilibrium with the same fixed hanging mass, the spring with the lower spring constant ($k$) has a larger potential energy $\because$ the displacement outweighs the spring constant.